Bangarang
Backgrounder1
February 2014
Marine Tetrapods
(of the Kitimat Fjord System)
Eric Keen
Abstract
Marine tetrapods are vertebrates secondarily adapted for marine environment who obtain most or all of their
nourishment from the sea. This includes marine reptiles, marine mammals (cetaceans, pinnipeds, sirenians, sea
otters, sea bats and polar bears) and seabirds. This Backgrounder reviews their general natural history and
compiles information relevant to the status, ecology and distribution of those marine tetrapods expected in the
Kitimat Fjord System. Of marine mammals, the Kitimat Fjord System is commonly host to two mysticetes, four
odontocetes, two phocids, one otariid, and one mustelid. Depending on how one deals with the seasonal use of
marine habitats, 35-55 seabirds are expected in the area (excluding shorebirds).
Contents
Natural History
Taxonomy
Marine tetrapods
Marine mammals
Seabirds
Evolution
Water: The subtle difference
Marine mammals
Seabirds
Biology
Anatomy, Morphology
Energetics
Diving
Life History – Marine Mammals
Life History – Seabirds
Foraging
Marine Mammals of the Kitimat Fjord System
Toothed cetaceans
Mustached cetaceans
Pinnipeds
Mustelids
Seabirds of the Kitimat Fjord System
Taxon by Taxon
Important Bird Areas (IBAs)
1 Bangarang Backgrounders are imperfect but rigorouss reviews – written in haste, not peer-reviewed – in an effort to organize and
memorize the key information for every aspect of the project. They will be updated regularly as new learnin’ is incorporated.
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Natural History
Taxonomy
For our purposes, tetrapods (amphibians, reptiles, birds and mammals) are considered marine if they obtain
most or all of their sea from the marine environment.
Marine Mammals
The term “marine mammal” is not a natural biological grouping; it encompasses 130 species of cetaceans,
pinnipeds (these are the two most common and well known marine mammal groups), sirenians, and fissipeds
(Carnivora members with separate digits, including the otters and polar bears), all of whom retrieve most of their
food from the sea. As mammals, all of these groups are endothermic, nurse live young, and have diagnostically
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mammalian skulls. As marine mammals, they obtain all their food from the sea . These disparate groups
represent 5 or 6 recolonizations of aquatic habitat. Marine mammal taxonomy and systematics is highly
controversial and currently in a state of flux. These marine mammal groups are united not by close relation, but
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by a similar story that has transformed their life histories and ecologies in shared respects .
Marine mammals are extraordinarily derived, rivaling the adaptive ingenuity of bats. To varying degrees and with
exceptions, all are streamlined and have reduced appendages, modified physiology and anatomy for thermoand osmo-regulation, unique strategies and “equipment” for foraging, enhancement or loss of certain senses,
and myriad internal adaptations to marine living. Their secondarily marine life has also fundamentally
restructured their life history, reproductive strategies, intelligence, and sociality. All marine mammals are directly
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or indirectly impacted by human activities, some to the point of extinction .
The zoogeography, distribution, and migratory behaviors of marine mammal species are highly variable and
prohibit summary. One available generalization is that little is known of the particular factors that limit the
occurrence of species. The physical and bathymetric features that drive megascale patterns in ocean circulation
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and productivity are ultimately responsible for many marine mammal distributions .
Cetaceans are a monophyletic group that diverged from other artiodactyls (even-toed ungulates) >50mya and
underwent punctuated periods of radiation, survived by ~86 extant species. ). As the most derived secondarily
marine mammal, they are completely independent of land, practically hairless, well-blubbered, and extremely
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hydrodynamic (fusiform bodies, no hind appendages, telescoped skull, etc.) .
The Cetacea can be split into two monophyletic groups: Suborder Mysteceti (baleen whales): 4 families, 14
species. Mysticetes have no functional teeth beyond the fetus stage, and both nostrils are present as blowholes;
their skulls are symmetrical, and they are universally large. The most speciose family is the Balaenopteridae,
the lunge-feeding, dorsal-finned rorquals, which includes the largest animals to have ever lived (i.e. the blue
whales). Other families are the Balaenidae (right and bowhead whales), Neobalaenidae (pygmy right whales,
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resurrected cetotheres), and Eschrichtiidae (gray whales) .
Suborder Odontoceti (toothed whales): 10 families, 65 species. Odontocetes bear homodont teeth, have
asymmetrical skulls, and all are known or assumed to echolocate. They are generally smaller than mysticetes,
but male sperm whales (the lone species of the family Physteridae) can be over 60ft long. Many odontocetes
are specialists at foraging at great depths, and include some of the deepest divers on earth. In addition to sperm
whales, families include the Kogiidae (2 species; pygmy and dward sperm whales), Ziphiidae (21+ species;
beaked whales), four families of river dolphins, all of whom returned independently of each other to freshwater
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture 2.
Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
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Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture 2.
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture 2.
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habitats (4 families, 4 genera, 4 species), the Monodontidae (beluga and narwhal), the Phocoenidae (porpoises;
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3 genera, 7 species), and finally, the Delphinidae (17 genera, 36 species, the largest being the killer whale) .
The Sirenia, the only marine mammal herbivores, boast a fossil record that extends back >50mya; they evolved
from proboscideans (shared ancestors of elephants and hyraxes). There are two families (Trichechidae, 3
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manatee species; Dugongidae, 1 dugong species) .
Marine mammals in the order Carnivora include all members of the Suborder Pinnipedia (fins modified as nondigited flippers; 34 species). Pinnipeds are a monophyletic group of amphibious carnivores that diverged from a
(likely) ursid ancestor 30-35mya. There are five major lineages of pinnipeds, three of which are extant (tusked
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odobenid walruses, 1 species; eared otariid seals, 16 species; and earless phoecid “true” seals, 19 species) .
All species are tied in some way to land, all have skin with hair underlain with a blubber layer, some exhibit
extensive sexual dimorphism, and all have small litters (~1 pup).
The marine fissipeds (Carnivora), otters and bears, are relative newcomers. Otters (Mustelidae: Lutrinae, six of
13 species are marine-living, 1 obligately marine) are only a few million years old. Polar bears, the only marine
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ursid, diverged from brown bears ~1.3 mya. It is the least aquatic and least derived of the marine mammals .
Another marine representatives of the Carnivora one species of the Ursidae (polar bear, require sea ice and
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land; 1 genus, 1 species) .
Within the Order Chiroptera, there is one bat species in the Noctilionidae that preys upon aquatic and marine
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fishes .
Identifying the representatives of these taxa can be difficult, but good identification guides are essential for
wildlife watching, research, and education programs. Virtually every marine mammal species exhibits variability
among its geographic populations. Significant dimorphism among sexes, life stages, seasonal appearances
(though less important in marine mammals), uncommon color morphs, individuals (perhaps due to scarring or
injuries), and sighting conditions – as well as the possibility of hybrids and intergrades between species -- may
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also confound efforts to identify and describe a species .
Seabirds
The term “seabird” is a loosely taxonomic grouping that encompasses ~350 species in many evolutionarily
disparate clades, including penguins, “tubenose” seabirds, tropicbirds, pelicans, frigatebirds, boobies and
gannets, cormorants, and gulls and terns and their close relatives. As birds, all of these groups possess
feathers, forelimbs modified into wings, no teeth, highly modified skeletons for flight, and an extensive airsac
system throughout their body. Birds are also homeothermic and oviparous. As seabirds, they obtain all or most
of their food from the sea. Notably, this group does not include sea ducks, osprey or sea eagles, and it does
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include species like gulls and terns who often obtain their food from land .
The penguins (O. Sphenisciformes, f. Spheniscidae, 6 genera and 18 species) are strictly marine, currently
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restricted to the southern hemisphere, and are primarily temperate and subpolar .
The “tubenoses” (O. Procellariiformes, 3 families) possess a diagnostic placement and shape of external
nostrils. The albatrosses (f. Diomedeidae, 4 genera, 21 spp.) boast extreme wingspans, juvenile plumage
wardrobes, and a poor ability to take off without wind or a running start. The fulmars, priors, petrels, and
shearwaters (f. Procellariidae) are gull-sized, strictly marine birds comprising 14 genera with 90 species; their
nostrils are united in a single tube on top of bill. The storm-petrels (f. Hydropbatidae, 7 genera, 24 spp.) are
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture 2.
Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
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Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture 2.
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture 2.
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Jefferson, T.A., M.A. Webber, and R.L. Pitman. 2008. Introduction. Marine Mammals of the World. Academic Press.
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Ballance, L. 2013. Seabird taxonomy. Marine Tetrapods Lecture, Week 2.
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Ballance, L. 2013. Seabird taxonomy. Marine Tetrapods Lecture, Week 2.
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even smaller, strictly marine, and they flap (no gliding). The diving petrels (f. Pelecanoididae, 1 genus, 4 spp.)
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are small birds restricted to the temperate Southern Ocean, and are excellent swimmers .
The tropicbirds (O. Phaethontiformes, 1 genus, 3 spp.) and Suliformes (3 families) used to be within the
Pelecaniformes (pelicans, 1 genus, 2 marine spp.), but have since been split. In the Suliformes, the frigatebirds
(f. Fregatidae, 1 genus, 5 spp.) are sexually dimorphic, eat flighted prey, and never land on water. The boobies
and gannets (f. Sulidae, 3 genera, 10 spp.) bear serrated bills, are sexually dimorphic, and are excellent plungedivers. The cormorants (f. Phalacrocoracidae, 3 genera, 41 spp.) practice foot-propelled diving and their
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feathers are not waterproof (which is why they sun themselves) .
38% of seabirds can be found in the Charadriiformes. This order includes the following seabird groups: the
phalaropes, a subfamily of the Scolopacidae, the skuas and jaegers (f. Stercorariidae, “raptors of the seabird
world”), the alcids (auks, puffins, auklets, murres, guillemots, and murrelets), and the gulls and terns (f. Laridae,
102 species). The larids are generalist and often opportunistic feeders, usually obtaining a portion of their food
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from terrigenous or human sources .
Evolution
Water: The Subtle Difference
Although taxonomically disparate, marine tetrapods have more or less converged in terms of physiology,
morphology, life history, and foraging strategy over deep time; this is because their transformation into
secondary marine forms has been guided by the same selective forces inherent to all life in water. The
differences between air and water may seem obvious, but their implications are profound and offer insight into
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the natural history of marine tetrapods . The selective forces common to marine tetrapods can be attributed to
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six properties of water that distinguish it from the terrestrial realm :
1) Water is more dense than air. As such, hydrodynamic efficiency is of prime importance and marine
tetrapod’s body plan has been thoroughly remodeled; appendages have adapted to push and steer
through the dense medium; skeletal structures have adjusted to support the immense musculature
required for propulsion; gravity is of reduced concern, releasing constraints on body size and the use of
the skeleton as a support structure; the unique suspension of food particles has created innovative
foraging strategies that were not available to vertebrates on land; and the enormous pressure
differences associated with a deep high-density medium has introduced new challenges for marine
tetrapods.
2) Water is thermally more inert than air. Means of maintaining homeothermy in the marine environment
have hence evolved, including blubber insulation and physiological methods of shunting heat to the vital
organs.
3) Water contains less dissolved oxygen than air, which marine tetrapods have avoided grappling with
by remaining tied to the surface for gas exchange.
4) Light transmission in water is greatly reduced, and certain wavelengths attenuate faster than others;
this governs the distribution of primary production in the ocean, and has pressed marine tetrapods to
develop sensory organs and methods other than sight.
5) Sound propagates faster and farther in water, which is a property that marine tetrapods have
exploited for orientation, finding food, and communication in the absence of amenable visual and
olfactory conditions.
6) The marine habitat is fundamentally different. It is defined not by vegetation or land forms, as on
land, but by the physical, chemical, and biological properties of water masses that are dynamic in both
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Ballance, L. 2013. Seabird taxonomy. Marine Tetrapods Lecture, Week 2.
Ballance, L. 2013. Seabird taxonomy. Marine Tetrapods Lecture, Week 2.
Ballance, L. 2013. Seabird taxonomy. Marine Tetrapods Lecture, Week 2.
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Ballance, L. 2013. The marine environment as a selective force for secondary marine forms. Marine Tetrapods. Scripps Institution of
Oceanography. Lecture 1.
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Ballance, L. 2013. The marine environment as a selective force for secondary marine forms. Marine Tetrapods. Scripps Institution of
Oceanography. Lecture 1.
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space and time. The consequences of this have been profound for all aspects of marine tetrapod
evolution, biogeography, ecology, physiology, and life history.
Marine Mammals
Before the origins and unity of a taxon can be discussed, it is necessary to define them. All pinnipeds share a
suite of characteristics in the morphology of their skull, jaw, humerus, and digits. The Pinnipedia and its three
families are now agreed to be monophyletic. There was some contention that the group is diphyletic, calling for
an origin from two carnivore lineages, the phocids from mustelids and the otariids and walrus from the ursids.
Pinniped monophyly is based on morphological data, including characters of the skull, humerus, digits, and
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limbs, and is supported by genetics . Pinnipeds diverged from their arctoid carnivore ancestors 27-25 mya.
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Most evidence supports a link with either ursids or mustelids, but that is still debated .
The earliest known fossil from this lineage is Enaliarctos (5 known species, 24-22mya), which had both
terrestrial and aquatic/marine features and exhibits the ancestral pinnipedimorh heterodont dentition. The three
pinniped families are diagnosed by several osteological and soft anatomical characters. Phocids the oldest
extant pinniped lineage. The earliest phocids are the oldest extant pinniped lineage, and the oldest phocid
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fossils come from the N. Atlantic .
Odobenids are known as early as the mid-Miocene 16-14 mya. The modern walrus is unmistakable with its pair
of elongated, ever-growing upper canines, found in both sexes. Several extinct lineages of walrus did not have
tusks. Morphological data support an alliance between phocids and odobenids, but molecular data support an
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otariid-walrus alliance .
The odobenid’s sister group, the otariids, appeared in the late Miocene. Their diagnostic pinnae and locomotion
on land set them apart. The otariids are divided into two subfamilies, the sea lions (Otariinae) and fur seals
(Arctocephalinae). Fossil evidence is very scant for otariids. Molecular evidence has revealed that both groups,
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fur seals and sea lions, are paraphyletic .
Together with sirenians, cetaceans are the earliest recorded marine mammals, appearing in the Eocene 53-54
mya. They are also the most diverse marine mammal group. 15 unequivocal features diagnose Cetacea,
including basicranial and dental features such as osteosclerosis (replacement of psongy bone with compact
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bone) .
Although originally placed with the fish (Linnaeus 1735), it is now thought that cetaceans diverged from
mammalian artiodactyls (even-toed ungulates). It was thought that the wolf-like mesonychian condylarths were
sister to the archeocetes, but now raoellids are thought to be sister. Hippopotamuses are the closest living
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relative to the cetaceans .
The earliest whales were archeocetes, a paraphyletic stem group of cetaceans. The archeocetes, or ancient
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whales, appeared in the fossil record in the early Eocene (60-50 mya) . The Pakicetidae are the oldest and
most basal cetaceans, known from early Eocene records and known to be partially aquatic (fossils found in
coastal estuarine habitats, bones thick, and ears adapted for underwater hearing).. A stepwise accumulation of
aquatic adaptations accrued as the lineage evolved throughout deep time. Hind limbs were reduced,
hyperphalangy evolved, and the skull telescoped. The Basilosauridae are late archeocetes, and one subfamily,
the Durodontinae, is sister to modern cetaceans. Compared to Basilosaurinae, durodontine archeocetes were
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small and dolphin-like .
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Ballance, L. 2013. Systematics and evolution of marine mammals. Marine Tetrapods Lecture, Week 3.
Berta et al. 2006. Chapter 3: Pinniped Evolution & Systematics. Marine Mammals: Evolutionary Biology.
Berta et al. 2006. Chapter 3: Pinniped Evolution & Systematics. Marine Mammals: Evolutionary Biology.
Berta et al. 2006. Chapter 3: Pinniped Evolution & Systematics. Marine Mammals: Evolutionary Biology.
Berta et al. 2006. Chapter 3: Pinniped Evolution & Systematics. Marine Mammals: Evolutionary Biology.
Berta et al. 2006. Chapter 4: Cetacean evolution & systematics. Marine Mammals: Evolutionary Biology
Berta et al. 2006. Chapter 4: Cetacean evolution & systematics. Marine Mammals: Evolutionary Biology
Ballance, L. 2013. Systematics and evolution of marine mammals. Marine Tetrapods Lecture, Week 3.
Berta et al. 2006. Chapter 4: Cetacean evolution & systematics. Marine Mammals: Evolutionary Biology
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According to the fossil record, and in agreement with molecular estimates, mysticetes and odontocetes split
from their common ancestor 35 mya. The two branches of modern cetaceans are each monophyletic. Modern
whales share derived characters not found in archeocetes, including fixed elbow joint and telescoping
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premaxillary and maxillary bones .
Extant mysticetes lack teeth (except in embryonic stages), but early fossil mysticetes were still toothed. Early on
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a toothless clade, the Cetotheriids, diverged and radiated . Mysticetes developed a large body size and large
head, and a shortening of the neck. Seven unequivocal synapomorphies diagnose mysticetes.The first baleenbearing mysticete fossils are described from late Oligocene beds in South Carolina. The “Cetotheriidae” has
historically been a diverse, catch-all group of extinct toothless mysticetes, but it has recently been resurrected
because the extant pygmy right whale is now considered a cetothere. Systematics of the four living mysticete
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families has been contentious .
Fossils of early odontocetes have been found as early as 33mya. They exhibit primitive dentition and rostra of
various lengths. An early branch, the squalodontids, are hypothetically the first to have developed echolocation.
Early on, odontocetes evolved homodonty and polydonty. An enormous diversity of odontocete lineages have
been evolutionary “dead-ends”, but were quite remarkable. One is the “walrus whale”, Odobenocetops, from the
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early Pliocene . Odontocetes have two diagnostic features that are also associated with echolocation: the
presence of a melon and cranial asymmetry (the right side is larger), but these features were absent from some
early, now extinct lineages. 14 unequivocal synapomorphies diagnose Odontoceti. In one hypothesis, beaked
whales are united in one clade with sperm whales (Physeteroidea); in another, beaked whales are positioned
with more crownward odontocetes. Regardless, both families are basal odontocetes. The status of
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Platanistoidea and the 4 river dolphin families has been contentious as well .
Seabirds
Birds: Birds are a monophyletic group that evolved from flying ancestors. As such, birds share synapomorphies
related to flight that make them lightweight (e.g., teeth absent and many organs reduced), streamlined (e.g.,
fusiform body covered in feathers), balanced centrally (i.e., flight muscles are located close to body’s central
axis), powerful (e.g., high body temperature, high-energy diet), and skilled at hunting from on high (i.e., visual
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acuity) .
The closest relatives to birds are the bipedal dinosaurs, Deinonychosaurian theropods. The earliest known
fossil bird is Archeopteryx from the late Jurassic; it was feathered, its forelimbs were modified into wings, and in
most ways intermediate between avian and reptilian forms. After the first avian radiation in the Mesozoic, there
was a cataclysmic decline at the K/T boundary (similar to other major groups) followed by an explosive radiation
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in the early Paleogene .
Seabirds: The group “Seabirds” traditionally includes the Sphenisciformes, Procellariiformes, Pelecaniformes,
and certain families among the Charadriiformes. This is not an all-inclusive group, and it also includes some
groups that contain freshwater or estuarine species. Broadly, the process of getting taxonomic classifications to
align with true (i.e., evolutionary) relationships has been arduous, but a synthesis of morphological and genetic
methods has shown tractable progress. Each order mentioned above has diagnostic characteristics and differing
degrees of diversity within it [see my lecture abstract for a summary of diversity]. These patterns in diversity
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suggest underlying patterns in geography or behavior .
Marine invasions by birds have occurred since the Cretaceous, perhaps induced by the established presence of
predatory dinosaurs and competitive land birds and mammals. However, marine systems in the Cretaceous
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Berta et al. 2006. Chapter 4: Cetacean evolution & systematics. Marine Mammals: Evolutionary Biology
Ballance, L. 2013. Systematics and evolution of marine mammals. Marine Tetrapods Lecture, Week 3.
Berta et al. 2006. Chapter 4: Cetacean evolution & systematics. Marine Mammals: Evolutionary Biology
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Ballance, L. 2013. Systematics and evolution of marine mammals. Marine Tetrapods Lecture, Week 3.
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Berta et al. 2006. Chapter 4: Cetacean evolution & systematics. Marine Mammals: Evolutionary Biology
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Ballance, L. 2013. Systematics & Evolution: seabirds. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 4.
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Ballance, L. 2013. Systematics & Evolution: seabirds. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 4.
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Brooke, M. de L. 2002. Seabird Systematics and Distribution: A review of current knowledge. In E.A. Schreiber and J. Burger (Eds.)
Biology of Marine Birds. CRC Press. Chapter 3.
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were also riddled with megapredators that challenged secondarily marine birds, and many of these early
lineages (such as the flightless Hesperornithiformes and the tern-like Icthyornithiformes) went extinct at the K/T.
The subsequent reinvasions of birds to marine systems were concurrent to (and possibly caused by) major
climatic and tectonic events, including the onset of the east Antarctic ice cap and the strengthening of the earth’s
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latitudinal thermal gradient .
Of the modern seabird lineages, which colonized the marine environment in three separate events, the
Procellariformes and their sister group, the Sphenisciformes, comprised the first re-invasion (65 mya or earlier,
perhaps in response to a “release” due to the decline of marine reptiles). Both groups originated in the southern
hemisphere, but the fossil record for the “tube-noses” is very poor. The penguins were diverse and distinct,
specialized divers by 40 mya in Oceania, 25 mya in South America, and 10 mya in Africa. Fossil penguins were
large, up to twice the mass of the largest penguins extant today. The earliest fossils of the Pelecaniformes
(including the Suliformes and Phaethontiformes), the second re-invasion, are from the early Eocene. Two
remarkable extinct groups from their ranks are the enormous Pseudodontorns (5-6m wingspan!) and the large
penguin-like Plotoperids. The marine Charadriiformes, the third re-invasion, are likely monophyletic, and
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radiated at the Oligocene-Miocene boundary .
The adaptive radiation of the Procellariiformes is extensive, successful, and remarkable. There has been debate
about the monophyly of tube-noses -- penguins and petrels may also be within the clade – and the phylogeny
within the Procellariiformes themselves, and within single species. A consistently high extinction rate among the
tube-noses has also confounded the fossil record and attempts at paleontological phylogenies. Hybridization
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may also be affecting the present-classification and known ranges of species . The fossil record suggests that
Procellariiformes have been diverse and abundant since the Pliocene, but they could have originated as early as
the Cretaceous. However, molecular clock results suggest isolation from a proto-Sphenisciformes ancestor only
36 mya. Their radiation probably occurred rapidly once the group was established. The group seems to have
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conformed to Cope’s Rule – the tendency to evolve toward larger body size .
Current distributions suggest that the initial tube-nose radiation took place in the southern hemisphere, perhaps
the southwest Pacific where penguins and mysticetes also radiated. Unfortunately, the fossil record for
Procellariiformes in the Southern Hemisphere is poor (elsewhere on earth, where the fossil record is better,
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albatrosses may be over-represented in collections due to their size) .
If indeed Procellariiformes and Sphenisciformes arose from a common ancestor, it makes sense that they
diverged in the south, while pieces of Gondwanaland were drifting into higher latitudes of the southern
hemisphere; Procellariiformes subsequently emigrated to lower latitudes and remained geographically isolated
for long enough to diverge from Sphenisciformes before recolonizing the Southern Ocean. However, landbridges, sea-level, climate, and tectonics have been so active and variable over recent deep time that the
present distribution of living species and fossils may not be clues to origins. These same forces -- the escalation
and recession of ice ages brought about transgressions and retreats of ice and sea level -- may have divided
populations and provided enough time for the vicariantly allopatric populations to become reproductively
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isolated .
Because of the prevalence of small predators throughout deep time on continents, even the early petrels likely
bred on isolated islands. The likely profound effect of high-level philopatry in early Procellariiformes could have
fostered the isolation of populations. But this philopatry could not have been total since some mechanism must
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be in place for exploring and expanding ranges in the event of natural disasters and habitat destruction .
Patterns & Puzzles: Seabird evolution presents many fascinating puzzles regarding phylogeography and
functional morphology. For examples, flightless forms occur only in high-latitude temperate and polar zones,
while tropical seabirds are all excellent gliders; this is likely because higher latitudes offer greater productivity,
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Ballance, L. 2013. Systematics & Evolution: seabirds. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 4.
Ballance, L. 2013. Systematics & Evolution: seabirds. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 4.
Warham, Ch 11. Evolution and Radiation (of Seabirds). Population Biology and Physiology of the Petrels.
Warham, Ch 11. Evolution and Radiation (of Seabirds). Population Biology and Physiology of the Petrels.
Warham, Ch 11. Evolution and Radiation (of Seabirds). Population Biology and Physiology of the Petrels.
Warham, Ch 11. Evolution and Radiation (of Seabirds). Population Biology and Physiology of the Petrels.
Warham, Ch 11. Evolution and Radiation (of Seabirds). Population Biology and Physiology of the Petrels.
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which is needed to support the energetically costly foraging strategy of diving. All seabird groups demonstrate
close convergent evolution, which is surely a vestige of the evolutionary “baggage” they all carry as terrestrial
vertebrates who turned volant then turned marine. Wing-propelled diving evolved in a minimum of four
independent lineages: penguins, alcids, plotopterids (extinct lineage), and diving petrels. These four groups
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demonstrate a continuum of specialization for wing-propelled foraging .
Distribution, diversity, and morphology influence each other dialectically. No seabird family is endemic to a
single ocean, and most are found in both hemispheres. Those that are restricted to a single hemisphere are
high-latitude species adapted to the underwater pursuit of prey. This makes sense, since swimming birds must
sacrifice flight efficiency to be so, and high prey densities are needed to support the energetically expensive
foraging strategy. In fact, most of the most abundance seabird species tend to be high-latitude species who
obtain their food by pursuing prey underwater, perhaps due to the increased productivity to be found there.
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Foraging technique seems to influence patterns in abundance and distribution .
There are stark differences between North Pacific and North Atlantic seabird assemblages, which may be due to
either circumstances of history (i.e., there used to be family x in this ocean, but it’s currently absent) or the lack
of ecological space (e.g., the rich auk and non-breeding shearwater communities of the N. Pacific has blocked
breeding shearwaters from colonizing). In some cases the species of one ocean are represented by sister taxa
in the other. The southern hemisphere has fewer land barriers to seabird distribution. Species can also replace
one another along latitudinal zones or clines, or at temperature or salinity discontinuities (e.g. eastern boundary
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currents) .
There are also patterns in morphology. Tropical species require longer wings, smaller bills, and less fat in order
to forage economically over large expanses of ocean, catching sparse and often mobile prey. Polar species,
however, have smaller wings to cope with stronger winds, small bills to catch abundant zooplankton, and large
fat deposits to survive stormy periods. For some seabirds, including the albatrosses, gadly petrels, southern
shags, and larger northern gulls, very similar plumages render their species boundaries are difficult to define.
While this may be because nature never fits neatly within human constructs, it may also be because the first
three of these groups are extremely philopatric to their natal nest sites. If birds sharing a nesting site also share
slight genetic adjustments to local conditions, there would be selection against intermingling phenotypes with
other colonies. But since birds are rarely dispersing to other colonies, there is no need for divergent plumage to
maintain genetic isolation, and morphology and plumage would be a poor guide in constructing the natural
history of individual species. The situation is different for gulls, who often comingle and share nesting sites. But
the fact that confusion occurs only for temperate gulls, not tropical species, suggests that fragmentation due to
glaciation or the like isolated populations and allowed some sort of reproductive isolation to evolve without the
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divergence of plumage .
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Ballance, L. 2013. Systematics & Evolution: seabirds. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 4.
Brooke, M. de L. 2002. Seabird Systematics and Distribution: A review of current knowledge. In E.A. Schreiber and J. Burger (Eds.)
Biology of Marine Birds. CRC Press. Chapter 3.
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Brooke, M. de L. 2002. Seabird Systematics and Distribution: A review of current knowledge. In E.A. Schreiber and J. Burger (Eds.)
Biology of Marine Birds. CRC Press. Chapter 3.
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Brooke, M. de L. 2002. Seabird Systematics and Distribution: A review of current knowledge. In E.A. Schreiber and J. Burger (Eds.)
Biology of Marine Birds. CRC Press. Chapter 3.
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8
Biology
Anatomy & Morphology
The external anatomy of marine mammals is selected to reduce drag and heat loss (this includes large size, a
complex skin structure featuring an insulating hypodermis, reduction of appendages to varying degrees, and
streamlining). Sexual dimorphism is also present in some clades. In contrast to cetacean skin, pinniped skin is
highly vascularized, is lubricated for waterproofing, and houses hair follicles and sweat/sebaceous glands.
Pinniped hair is very dense, is organized into clusters of guard hairs and underfur hairs, and is molted once a
year, but it pales in density to that of otters. In cetaceans, dorsal fins and flukes are present; these are
extensions of the skin composed of poorly vascularized, cross-lain, stiff fibers that provide a means of
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thermoregulation and stability when swimming .
The skull protects particularly vulnerable vital organs and sensory functions, and is composed of six bones that
must be known to appreciate the adaptive morphology of marine mammals: the maxilla, pre-maxilla, nasal,
frontal, parietal, and supra-occipital. In teleost fish, cranial bones are thin and plate-like and contribute to their
overall fusiform shape. Pinnipeds, which can represent a terrestrial foil to fish and cetaceans, require skeletal
support against gravity, protection against blows from competing peers, protection from extreme temperatures,
and an increased brain case. As a result, bones are heavy and fused, the skull is not fusiform, and skull bones
are increased to house the brain. Odontocetes, a secondary marine form, must be streamlined, powerful, able
to breathe at the surface easily, and able to house a large brain (mysticetes face similar pressures, but the need
to house baleen in the maxilla is an additional concern). As a result, the neurocranium is re-arranged and
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telescoped, and the axial skeleton is greatly modified .
Propulsion in marine mammals is derived from the movements of paired flippers (pinnipeds and sea otters) or
the vertical movement of caudal flukes (cetaceans and sirentians). The internal functional morphology of the
marine mammal skeleton is best seen when compared among both marine mammals and another marine form,
the teleost fish. Bone first evolved in the scales of Agnathan fish to provide rigidity, support, protection, and the
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storage of phosphates and calcuims . In fish, bones are thin, cervical vertebrae are reduced and fused because
the head does not need support, vertebrae are not differentiated and equally flexible along the animal’s length;
girdles provide attachment points for appendages, which are gragile. In pinnipeds, we see a compromise
between terrestrial and marine pressures. Cervical vertebrae are strong, their vertebrae are differentiated for
different functions, neural spines and processes are well-developed to house muscle mass, girdles are strong
and limbs are long and thick but streamlined, and articulating zygapophyses facilitate the specific locomotive
needs of the two largest pinniped groups. The different locomotive means of otariids and phocids, both in land
and water, are made manifest in the details of their skeleton. For example, otariids propel themselves with
pectoral appendages, while phocids propped with pelvic appendages, and the skeleton of each group is
modified accordingly. Another example: the pelvic girdle facilitates forward rotation of hindlimbs in otariids, who
are more terrestrially competent, while the pelvic girdles and appendages articulate at a posterior angle to
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facilitate swimming . Fore- and hindlimbs also reflect these different strategies. In general, appendages are
shortened, digits are elongate, and both are dorsoventrally flattened. Skull morphology accommodates muscles
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for foraging methods (e.g. large-prey carnivory in otariids and phocids, suction-feeding in walrus) .
Similarly in cetaceans, feeding governs skull morphology and locomotion governs overall skeletal structure, but
both selective pressures are at work. Cetaceans, like phocids and sirenians, are caudal oscillators; there was an
evolutionary progression from pelvic-phase, caudal-undulation phase, to the present caudal-oscillation phase
present in durodontids (the first to bear flukes). The vertebral column is greatly modified to house enormous
masses of muscle for caudal oscillation. Forelimbs are greatly modified for steering and stability, digits are
increased (“hyperphalangy), and the pectoral girdles are flat, wide, and fan-shaped. The pelvic girdle is reduced
and useless. The flukes are an outgrowth of the caudal region, and serves a thermoregulatory purpose in
addition to locomotion. The fluke and the rigid dorsal fin are composed of layered, cross-hatched fibrous tissues.
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Ballance, L. 2013. Anatomy & morphology: marine mammals. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week
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Flukes derive lift-generated thrust on both the upstroke and down stroke. Killer whales are among the fastest
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cetaceans, reaching 50 km/hr at top speeds .
Cetaceans represent secondary fully marine forms; their cervical vertebrae are generally fused, the spine is
greatly developed for muscle attachment and flexibility, and appendages are shortened and dorso-ventrally
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flattened while digitation is increased for increased hydrodynamics and surface area . The cetacean skull is
telescoped, which has altered the size, shape, and relationship of the many skull bones. Odontocete skulls
display cranial asymmetry (hard- and soft tissue is enlarged on the right) as a result of the evolution of
echolocation. The dense odontocete rostrum is also implicated in audition. In mysticetes, the rostrum is convexly
arched to increase engulfment capacity and house baleen. Mysticetes have two unbranched nasal passages;
odontocetes have one and their associated organs boast incredible modifications for echolocation (e.g. phonic
lips, spermaceti in sperm whales, melons, etc.). The mandibles of cetacean groups are highly specialized for
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their foraging strategies .
Sirenians are leisurely caudal oscillators; as herbivores, speed is not a selective pressure. However, forelimbs
remain well-developed in sirenians, as they are used actively in food handling and steering. Sirenians also have
a vestigial pelvic girdle. Their heavy bones and horizontal bones maintain neutral buoyancy. Sea otters have
blunt skulls, elongate bodies, and short forelimbs. The hindlimbs of sea otters are so relatively large that
terrestrial locomotion is clumsy. In water, sea otters paddle with pelvic appendages and pelvic undulation. Few
data are available for polar bears, but they do not seem to be greatly modified for marine life. Their plantigrade
feet provide drag-based thrust when the animal swims with crawl-like strokes. On ice, these huge plate-like feet
distribute their weight and tiny papillae increase friction with the ice. Their disproportionately large claws enable
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them to grip the ice and their prey .
Physiology
Physiology is the regulation of the internal environment to maintain stasis at an optimal state for biochemical
reactions. In the aquatic environment, the high heat capacity of water, its low concentration of oxygen,
increasing pressure with depth, and high salinity (for marine systems) opposes homeostasis in derived
organisms. Marine tetrapods must maintain body temperatures permanently above ambient water temperature.
Heat is lost most readily through conduction (body in contact with cold water) and convection (movement of fluid
over body). To thermoregulate, several adaptations have developed. A large body size decreases the surface
area to volume ratio, minimizing the conductive surface and facilitating heat retention. Fur and blubber reduce
the thermal conductivity of a tetrapod’s surface, providing insulation. Increasing the thickness of this insulating
surface also conserves heat. Dynamic adaptations are also in place for thermoregulation, including controlled
blood flow to the body surface and countercurrent exchange (CCE). Versions of CCE can be found in all aspects
of physiological relation, pointing to its importance in the evolution of homeostatic forms. In general, CCE
functions by running two bodies (e.g. transport canals) in opposing directions at close proximity, such that the
substance within them (e.g. heat) is passed between the two and thus conserved. CCE occurs in the dorsal fins
and flukes of cetaceans. Another dynamic adaptation is increasing metabolic rate (i.e., activity level) when the
body drops below a certain threshold. Heat dissipation can also be a priority for the largest organisms and in low
latitude environments. Dissipation can occur by increasing blood flow to surface tissues or vasoconstriction in
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countercurrent exchange .
Oxygen levels & diving: In marine mammals the nares are positioned and sized to maximize oxygen intake
and use. Most deep-diving mammals have flexible chest walls and reinforced trachea (and larynx in cetacean),
which lead to the collapse of the lungs at depth so that they are virtually airless. The prevents nitrogen narcosis
after deep dives and aids in buoyancy regulation. Deep-diving marine mammals have lower residual lung
volumes, meaning the lung empties more completely during exhalation and gas exchange is more thorough and
efficient with every breath. Lungs are proportionally less voluminous in marine mammals, which makes sense
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Ballance, L. 2013. Anatomy & morphology: marine mammals. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 4
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because the danger of embolism prevents the organ from being an oxygen store during diving. But lungs in
cetaceans are less lobed, more sac-like, and more rigid due to cartilaginous reinforcement. Sirenian lungs are
extremely elongate, occupying almost the entire length of the body cavity, and facilitate buoyancy control. To
cope with the asphyxia and hypercapnia associated with a dive, marine mammals minimize oxygen use via
bradycardia (pronounced decline in heart rate) and selective ischemia (regional vasoconstriction). Breathing
patterns in marine mammals vary, but are characterized generally but extremely rapid and consistent exhalation
and inspiration rates with each breath. The blue whale can empty their lungs of 1500 liters of air and refill them
in as little as 2 seconds. Cetaceans typically dive with full lungs, while pinnipeds often exhale prior to diving. The
visibility of a whale’s blow is due to a mixture of vapor (due to heat in exhaled air) and seawater entrained into
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the exhaled column of air at the sea surface .
Water pressure & diving: Many marine tetrapods dive to obtain food or avoid predation. But the marine
environment poses two major challenges to diving: the lack of oxygen and the great pressures at depth.
Abdominal organs and muscle can function anaerobically, but the brain must be consistently supplied with fresh
oxygen. To maximize dive time without new oxygen, marine tetrapods maximize O2 storage and minimize its
rate of use. Lungs are not a major oxygen store for marine tetrapods, but they have evolved to exchange gases
incredibly efficiently at the surface. Instead, blood and muscle are the major oxygen stores, and the
concentration of hemoglodin and myoglobin, respectively, is correspondingly high. To minimize oxygen use,
diving tetrapods implement (1) changes in circulation (bradycardia, vasoconstriction, and shunting of blood to
highly vascularized “rete mirabile”), a decrease in metabolic rate (by shutting down visceral organs and
bradycardia), and anaerobic metabolism in peripheral muscles (which may be the ultimate limiting factor in dive
duration). It is disadvantageous to push dives into the anaerobic zone, because over repeated dives the time
required to recover at the surface diminishes overall foraging time at depth. Increasing pressure with depth
present challenges in gas exchange, but to accommodate this pressure, air spaces have been eliminated (e.g.
in the middle ear and sinuses) and the respiratory anatomy has evolved perform a graded collapse of the lung
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with increasing depth .
The diving abilities (in depth or duration) of marine mammals varies greatly. The effects of pressure and breathholding of the diving animal involves circulatory, respiratory, and behavioral changes. Sustained activity during
apneic conditions requires anaerobic metabolism in some parts of the bodies, which causes lactic acid and other
metabolic by-products to accumulate. During a dive, marine mammals undergo important circulatory changes.
Their hearts are capable of greater anaerobic capacity; the ascending aorta is bulbous and expanded, which
dampens blood pressure pulses to organs at each beat; groups of blood vessels (retia mirabilia) act as blood
reservoirs during vasoconstriction; and enlarged and complex somatic veins (in pinnipeds in particular); higher
blood volumes, with higher concentrations of hemoglobin (and especially myoglobin in muscle cells), which are
the most important oxygen storage sites in marine mammals. High myoglobin count is a critical adaptation for
diving. The large spleen of pinnipeds may also serve as a blood or oxygen store, but cetaceans have very small
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spleens .
In addition to its coupling to physiological capability, diving ability is also determined by body size, ecological
niche, life-history strategy. There are phylogenetic patterns to be seen in the dive behavior of marine mammals;
for example, many phocids are incredible divers, especially the largest elephant seal species, whereas otariid
sea lions dive shallowly, briefly, but frequently. The aerobic dive limit of an animal, developed by Kooyman, is
the longest dive a species can do that does not lead to an increase in blood lactate concentration during the
dive. If anaerobic respiration does occur, a recovery period at the survey is required. Many cetaceans, however
(the deepest divers excluded), often dive shorter than their aerobic dive limit, either due to the shallow
distribution of their prey or the energetic cost of foraging. Otters dive in coastal habitats, with long recovery
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periods; polar bears are poor divers; most sirenian dives are 5 minutes long, but can be as long as 20 minutes .
Osmoregulation: In a marine environment, tetrapods are challenged to obtain water, conserve it, and excrete
salts. The object of osmoregulation is to maintain a body-water volume and composition within some normal
range. Within this range, vertebrates can maintain blood pressure and flow, facilitate biochemical processes,
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Ballance, L. 2013. Physiology. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 5.
Berta et al. 2006. Respiration & Diving Physiology.
Berta et al. 2006. Respiration & Diving Physiology.
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and regulate cell volume and electrical balance. Quantifying water and sodium balance can provide insight into
the ecology and health of marine mammals and birds (including the constraints on extreme behavior, such as
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flight speed, time-at-sea, migrations, and fasting) .
Marine mammals obtain water from their prey and from their own metabolic reactions. Marine mammals are
hypoosmotic (their body fluids have a lower ionic content than seawater, and they are constantly losing water to
the environment). Marine mammals drink by eating, getting water from the food they eat (some warm-climate
seals and otters drink seawater, a behavior called mariposia). They reduce water loss by excreting concentrated
urine. Marine mammal kidneys are large and (except for the sirenians) reniculate (each kidney is made of
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discrete lobes that each act as a small individual kidney), rendering kidney function highly efficient .
Birds can gain water through their food (predominately), drink (less so), or as a byproduct of oxidative
metabolism. The water content of their food is typically high, but relative intake rates of water and sodium
depend on their prey (invertebrates are usually osmoconformers). Well-developed salt glands may compensate
for high-saline prey, and chicks may be fed osmotically modified boli from the parent’s gut. Marine birds do
ingest seawater, for a minor part of their hydration needs. Water is provided via metabolism most when the
biomass being metabolized are lipids, but at most provides 15% of the total water available from ingested
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foods .
Birds lose water via either evaporation or excretion. Water loss by evaporation occurs both through the skin
(insensible or cutaneous evaporation) and via exhaled air. Cutaneous evaporation is driven by a gradient of
vapor density within and without the bird’s body, while respiratory evaporation occurs because air is warmed
and humidified as it is respired. Some birds pant or perform gular fluttering to exacerbate respiratory
evaporation. Birds can excrete water and ions via the kidney-cloaca pathway, a continuation of that pathway to
the colon for ureic modification, or salt glands (which primarily excrete ions at very little water loss). Avian
kidneys function similarly to those of other vertebrates, generally with a larger number of nephrons with small
glomeruli. Their loops of Henle enable birds to produce highly concentrated urine, but perhaps not be
significantly better than terrestrial birds. Birds can reduce their glomerular filtration rate (GFR) using a modified
renal portal system, which is particularly adaptive in marine lifestyles. Kidneys also eliminate nitrogenous
wastes, excreting it primarily as uric acid and urates; this is particularly critical for processing the high-protein
diets of marine birds. The avian colon receives inputs from both small intestines and kidneys, causing it to serve
as an integrator of excretory loss of water and ions (for example, the colon might reabsorb salt so that it can be
excreted with less water loss through the salt glands). Kidneys predominately excrete ions and water, while salt
glands excrete the salt itself. Ten avian orders bear supra-orbital salt-secreting glands, which are largest in
marine species. The salt glands excrete solutions that are nearly pure NaCl (most concentrated in
procelariiformes). The glands typically hypertrophy after elevated salt intake or as part of an annual cycle of
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physiological adjustment .
Total body water (the percent of the body that is water) is ~60% for terrestrial birds, but 44-52% in marine birds.
This may be due to higher proportional mass in feathers, fat content, or demography (marine birds are longlived, and older birds are less “watery”). Water turnover rates (determined using isotope tracers) increases as a
function of body mass, but less active species have lower water fluxes than active animals. Sodium in the body
must be maintained at an optimal level (or pool size), which is similar for terrestrial and marine birds. Sodium
flux is measured by the intake rate and sodium content of food and drink (the two sodium intake pathways for
birds). Sodium flux increases with body mass, and seabirds have higher fluxes than terrestrial species. In all
these flux rates and proportions, there are patterns that reflect phylogenetic relationships and ecological kinship.
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Osmoregulation may vary by season and ontogenetic state as well .
Energetics
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Schreiber, E.A., and J. Burger, eds. 2001. Chapter 14: Water and Salt Balance in Seabirds Biology of Marine Birds. CRC Press.
Berta et al. 2006. Energetics.
Schreiber, E.A., and J. Burger, eds. 2001. Chapter 14: Water and Salt Balance in Seabirds Biology of Marine Birds. CRC Press.
Schreiber, E.A., and J. Burger, eds. 2001. Chapter 14: Water and Salt Balance in Seabirds Biology of Marine Birds. CRC Press.
Schreiber, E.A., and J. Burger, eds. 2001. Chapter 14: Water and Salt Balance in Seabirds Biology of Marine Birds. CRC Press.
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Energetics is a field that evaluates the energetic costs and benefits of life processes. For marine mammals, the
major energetic costs are metabolism, thermoregulation, locomotion, and osmoregulation. The high density,
viscosity, thermal conductivity, and salinity of water pose special challenges to the marine tetrapod body.
Metabolic rates can be measured in a variety of ways, and comparing rates depends on the use of standardized
methods involving both units and the biological state of the animal (basal, resting, and field/mean daily). Kleiber
(1947) fit a curve to the correlation between basal metabolic rate and body size (The Kleiber Curve). Resting
and field/mean daily metabolic rates (RMR and MDMR, respectively) are more feasibly measured in the field.
Marine mammals may have higher metabolic rates than would be expected by the terrestrial Kleiber Curve, but
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it remains debated .
Thermoregulatory adaptations allow marine mammals to live in a cold, highly conductive medium. To reduce
heat loss, marine mammals have evolved large body size (low surface-to-volume ratios), increased insulation,
and heat-conserving vacular counter-current systems. Marine mammals span a body mass range of ~4 orders
of magnitude, but they are almost all large to their terrestrial relatives. Large body size leads to lower surface
area relative to volume, fostering heat retention. Higher activity levels and reduced appendages supplement
these heat conservation methods, as does dense fur or blubber. In addition to insulation, blubber provides food
storage, hydrodynamic molding, buoyancy, and streamlining. The insulation capacity of blubber is a function of
its thickness, lipid content, and peripheral blood flow. Like humans and other mammals, the pups of some seal
species are born with brown fat, which can be metabolized to produce heat for the body. In pinnipeds, the
difficult of thermoregulating in air limits distributions antitropically. Marine mammals also reduce heat loss by
controlling peripheral blood circulations via CounterCurrent vascular Heat Exchange systems (CCHEs). These
systems maintain a heat differential between oppositely directed flows of blood; this increases the amount of
heat transferred. CCHEs are associated with dorsal fins, flukes and reproductive organs, but also in the face,
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jaw and spinal cord (manatees) and mouths (balaenids) .
Due to the density and viscosity of water, swimming and diving in it comes at great energetic cost. The body
shapes of marine mammal are compromises among a variety of opposing forces and selective pressures,
including frictional drag, pressure drag, wave drag, induced drag and shape drag (in balaenopterids during
feeding). The fineness ratio is a measure of streamlining in aquatic organisms. The Reynolds number (R) is a
comparative indicator of the forces acting on submerged bodies. The largest whales have some of the highest
Reynolds numbers in the living world. The locomotive efficiency of body forms can be compared using the metric
Cost of Transport (COT), the power required to move a mass a given velocity. COT decreases with larger
bodies, and is relatively very low in cetaceans. Behavioral adjustments, like wave riding, drafting, and
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porpoising, increase locomotor efficiency at the surface .
Life History -- Marine Mammals
The reproductive strategies of marine mammals are diverse and variable, and understanding them provides
insight into evolutionary patterns, as well as into conservation priorities; populations with more structure and
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stringent mating systems may be less able to adapt to environmental disturbances .
All marine mammal groups share reproductive features that stem from their shared placental mammalian
heritage. Due to mammalian male heterogamy, male to female ratios in marine mammals are confined to very
close to 1:1, even though polygynous systems may be more adaptive with different ratios. The term “breeding”
encompasses both mating (mate selection and copulation) and parturition (calving or pupping); the fact that
males only need be involved in the former structures the mating system in many mammals. The reproductive
structures are also typically mammalian. Pinnipeds possess a baculum (penis bone), whereas cetaceans and
sirenians do not and can retract their penis fully into the body. Mass-specific testes weight is an indicator of
mating systems (large testes imply more male competition, smaller testes imply more stable mating pairs). In
female whales, the corpora albicans (the hardened remains of a post-birth corpus luteum) remains for the
entirety of an animals life, providing a record of past ovulations. Cetacean mammae are long, flat glands along
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Berta et al. 2006. Energetics.
Berta et al. 2006. Energetics.
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the belly, and each open to single nipples retained within mammary slits. The two mammary glands of sirenians
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are located in the armpits. The size and number varies for otariids and phocids .
Marine mammals are large-bodied, long-lived, and k-selected (evolved to maintain stable population sizes near
carrying capacity). These features case them to be slow to mature and reproduce. The few offspring they
reproduce are intensely nurtured. Many marine mammal populations are in a state of recovery from humancaused depletion, and others are currently being depleted. This may cause current life history parameters to be
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different from those during periods of stable populations . Individuals tend to act to maximize reproductive
success, and males and females are subject to very different selective pressures. These two facts structure the
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life histories and mating systems of all marine mammals .
The trade offs between energetic investment and reproduction can govern life history strategies. It is
energetically expensive to provision offspring until they are nutritionally independent, and this task almost
always falls on the mother. Maternal investment strategies include fasting (phocids and large mysticetes),
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foraging cycle (otariids and other groups), and aquatic nursing (odontocetes, sirenians, and the walrus) .
Marine mammal reproduction consists of a cycle of events regulated by nervous and endocrine signals. Estrus
is the time period of maximum reproductive receptivity in female mammals; in phocids and otariids estrus is
monestrous (once a year) and postpartum, closely following parturition. Walruses are polyestrous (multiple
cycles per year). Less is known for cetaceans. Sirenians are polyovular, which might be necessary to produce
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sufficient progesterone to maintain pregnancy .
Gestation period roughly relates to the size of the fetus. Mysticete gestation typically lasts 10-13 months, in
odontocetes (who generally have less rigorous migration regimes) it is 7 to 17 months. Annual patterns are
practical for species that disperse broadly outside of the breeding season, for example to migrate to a summer
foraging ground. Sirenian gestation is 1 year. Pinnipeds, sea otters and polar bears have seasonal delayed
implantation to help fit reproduction to an annual cycle. All pinnipeds give birth out of water, but cetaceans and
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sirenians copulate and give birth in water. All marine mammals except polar bears have single offspring .
Mating systems of marine mammals include promiscuity (several males mating with a group of females) and
polygyny (male mates with many females). Like all mammals, marine mammals are predisposed to polygyny
due to the different reproductive physiology and anatomy of the two sexes. Sexual dimorphism in size,
proportion or ornamentation can occur in species whose males compete for females. We poorly understand the
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mating systems of many species, particularly large cetaceans .
Pinniped mating systems range from promiscuous to the unmatched extreme of polygyny in mammals. Most
phocids fast while nursing, while most otariids feed. Phocids typically have very brief lactation periods to
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minimize time above-water vulnerable to predation . All otariids and many phocid species are polygynous. The
half of pinniped species that give birth and mate on land are all strongly sexually dimorphic and polygynous. A
third of pinnipeds (walruses and seals) give birth on ice but mate in the water. Lek-like behavior might occur in
walruses and two species of otariid. The degree and type (resource-defense, harem defense, etc.) of polygyny
is largely determined by how tightly females cluster during breeding, the extent to which males can limit the
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access of other males to females, and the environmental context . There can be advantages for the females to
their clumping in harems, which is during the most vulnerable part of their life history. The inner females are
protected from other males and from predation. Other phocids and walruses mate in water or on ice, meaning
73 Berta et al. 2006. Chapter 13: Reproductive structures, strategies, and patterns.
Berta et al. 2006. Chapter 14: Population structure and dynamics.
Mesnick, S. 2013. Reproduction, mating systems and life history in marine mammals. Marine Tetrapods, Scripps Institution of
Oceanography. Lecture, Week 5.
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Mesnick, S. 2013. Reproduction, mating systems and life history in marine mammals. Marine Tetrapods, Scripps Institution of
Oceanography. Lecture, Week 5.
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Berta et al. 2006. Chapter 13: Reproductive structures, strategies, and patterns.
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mating is dispersed and sexual dimorphism is reduced . All territorial and hierarchical systems are subject to
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cheater strategies by subdominant males .
Most cetaceans and sirenian species are promiscuous. Mysticetes are typically less social than odontocetes,
who often live in structured social groups, or schools. Mysticetes exhibit reverse sexual dimorphism in which
females are larger than males. Manatees are solitary for most of the year, but mating herds occur in warm
season months in highly seasonal environments. Less is known regarding dugong mating systems, but the
erupted tusks in males may play a role in sexual selection. Sea otters and polar bears are polynygous and
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sexually dimorphic .
Cetaceans mate, give birth, and nurse underwater. We know a lot about only a few cetacean species; we know
very little about the rest. Reproductive strategies vary substantially. Mysticete species are relatively solitary, and
their reproductive cycle must fit with their annual migrations between breeding and feeding grounds. Many
odontocete species are highly social, exhibiting behaviors of altruism and succor. These bonds increase fitness
by increasing juvenile fitness, protecting the group from predation. Those that forage in groups tend to be of
similar size, due to the logistics of the hunt. There are also matrifocal bonds in some species such as killer
whales, in which there is a long period of calf dependency. Sperm whale mothers have been known to lactate
for up to 13 years! Some social species have senescent females, matriarchs who serve as repositories of socialecological knowledge. Sperm whales exhibit remarkable sociality, remaining cohesive and devoted to each other
even when under attack from killer whales. Females have been found lactating when they do not have calves of
their own, suggesting that allomaternal behavior occurs. There is an emerging view of “kith and kin” for sperm
whales, in which there are “groups” and “unity” of females and dependent young in a cluster of closely related
animals. In cetacean males, cooperation and alliance-forming often occurs in addition to competition. Pre-mating
modes of competition include contests (using weaponry such as large bodies, melons, tusks, and heads
reinforced with thick osteology), scrambles, and mate display (e.g., humpback whale song). Post-mating
competition includes sperm competition; the inordinate mass-specific size of testes in some species, like the
right whale, suggests promiscuous mating systems in which sperm competition occurs. Low mass-specific
testes size, such as in blue whales, may be evidence of more stable, less competitive mating systems. As in
other clades, sexual selection can fuel diversity in cetaceans (e.g. the Mesopolodon beaked whales, the most
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speciose genus of cetaceans) .
Life History -- Seabirds
Relative to diverse reproductive and mating systems in marine mammals and land birds, those of seabirds are
highly stereotyped. The seabird life strategy must accommodate both breeding on land and feeding in the sea.
This predicament confines seabird life history and ecology to follow certain patterns, known as the “Seabird
Syndrome”. Lack’s Paradigm states that these patterns evolved primarily due to constraints on food availability
during breeding period, when densely aggregated breeding pairs are central-place-foraging on limited food
resources within a radius (“Ashmole’s Halo”). Ashmole’s Paradigm states that this scenario will cause seabird
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life history traits to evolve toward lower reproduction and higher adult survival .
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The Seabird Syndrome is typified by the following features common to nearly all seabirds :
(1) Colonial breeding: despite many disadvantages to colonial breeding, 98% of seabirds do it. This is most
likely due to the shortage of nesting sites and the social stimulation that can synchronize reproduction and
therefore breeding success. Colony size corresponds to foraging range, and most seabirds have annual
breeding cycles timed to peaks in productivity at their latitude.
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Mesnick, S. 2013. Reproduction, mating systems and life history in marine mammals. Marine Tetrapods, Scripps Institution of
Oceanography. Lecture, Week 5.
Berta et al. 2006. Chapter 13: Reproductive structures, strategies, and patterns.
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Berta et al. 2006. Chapter 13: Reproductive structures, strategies, and patterns.
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Mesnick, S. 2013. Reproduction, mating systems and life history in marine mammals. Marine Tetrapods, Scripps Institution of
Oceanography. Lecture, Week 5.
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Ballance, L. 2013. Reproduction, mating systems, life history strategies in seabirds. Marine Tetrapods, Scripps Institution of
Oceanography. Lecture, Week 5.
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Ballance, L. 2013. Reproduction, mating systems, life history strategies in seabirds. Marine Tetrapods, Scripps Institution of
Oceanography. Lecture, Week 5.
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(2) Small clutch sizes: This may be related to restricted ability to provision chicks when feeding far from nest
sites. Clutch size tends to be higher in species feeding nearshore and in higher latitudes than those in oceanic
waters and at low latitudes. Some seabirds lay 2 eggs, and obligate or facultative siblicide occurs.
(3) Long period to chick independence: Feeding far from the colony slows the energy provision rate to
chicks. Most seabird hatchlings tend to be semialtricial and unable to thermoregulate, almost entirely reliant
upon parents for survival. Upon hatching, meals are frequent and small; after thermal independence, meals
become larger and more infrequent; fledging (complete independence) does not occur until chicks are as
massive or more so than their parents.
(4) Bi-parental care, monogamy, and reduced sexual dimorphism: central place foraging in competitive space
and the need to constantly incubate the chick make it difficult for a single parent to support a chick. This has led
to biparental care and therefore monogamy among seabirds. Established pairs tend to have higher breeding
success than new pairs.
(5) Delayed reproductive maturity: Because juvenal survival rates can be low, low annual reproductive output
can be compensated with longevity, and long-term reproductive bonds require significant time to forge, delayed
reproductive maturity is a common feature of seabird life histories.
(6) High adult survival and long-lived: Albatrosses can live as long as 70 years!
Demography is the study of the size and structure of populations and of the process of replacing individuals
constituting the population, and allows us to forecast population growth. Demography also provides insight into
the strength of selective pressures on life history traits. Within the confines of their phylogenetic Bauplans,
taxonomic groups employ different “demographic tactics”, a complex co-adaptation of demographic parameters,
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to remain competitive within a certain ecological and environmental context .
Compared to other birds, seabirds have lower fecundity, breed at an older age and have higher adult survival.
Within seabirds, extensive differences exist between and within orders. Fecundity (the product of clutch size,
breeding frequency, and breeding success) is generally low, with many groups having single-egg clutches.
Clutch size is probably limited by the ability to provide food for offspring in densely packed breeding colonies
(Lack’s Paradigm). If the goal is to maximize overall reproductive rate, there must be a balance between present
and future reproduction (allocation), and many seabirds are “prudent parents” who limit risks of increased
mortality when reproducing. There is a tight correlation between fecundity and life expectancy. Late age at first
breeding is common among seabirds, and typical of long-lived species. There seems to be a strong
phylogenetic effect on demographic tactics with the four (former) families of Pelecaniformes, which all rank
separately on a fast-slow turnover gradient. In contrast, groups within the Procelariiformes are scattered along
this gradient. This may be so because demographic traits are more phylogenetically fixed in the
Procelariiformes. Families with a restricted range along the fast-slow gradient likely face similar environmental
conditions, whereas disparate ranges imply that they face a diversity of habitats. There can also be
demographic convergence among unrelated seabird groups due to their similar ecological and environmental
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circumstances .
Examining demographic differences within species best reveals the influence of the environment in demographic
tactics. Some species with geographically separate populations, such as wandering albatross, show very
homogenous demographic traits, suggesting that all populations rely on similar resources. In other species, such
as black-browed albatrosses, demographic traits can vary dramatically between oceans and among populations.
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These differences highlight the importance of the marine environment in shaping seabird demography .
Seabird populations are mainly regulated by food availability in a density-dependent way around breeding
grounds, but we still don’t know how density-dependence affects populations. Demographic parameters,
particularly fecundity, may vary according to environmental variability as well, and two general tactics might be
selected for: 1) High-dispersal species: The low susceptibility of long-lived far-ranging seabirds to food supply
variability is probably due to their mobility, able to leave unsuitable areas and find food elsewhere. The mostdispersing seabirds are more resilient to local variability, and therefore do not need to compensate with high
fecundity. (2) “Guano” seabirds: low-dispersal resident seabirds, such as cormorants and pelicans, must have
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Henri Weimerskirch. 2002. Chapter 5: Seabird Demography & its relationship with the marine environment. in Schreiber & Burger 2002.
Henri Weimerskirch. 2002. Chapter 5: Seabird Demography & its relationship with the marine environment. in Schreiber & Burger 2002.
Henri Weimerskirch. 2002. Chapter 5: Seabird Demography & its relationship with the marine environment. in Schreiber & Burger 2002.
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high potential fecundities in the case of a spike in adult mortality. In periods of favorable conditions, density91
dependent feedbacks regulate the population .
Understanding seabird demography requires long-term studies of populations with marked birds, which is
difficult when researchers have the same lifespan as the birds they are studying and an important part of the
population (young birds) is not accessible to study. Seabird demography will benefit from more intensive
marking of fledglings and studies on dispersal rates. Comparing populations of the same species living in
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contrasted environments is probably more promising .
Food
Marine Mammals: All marine mammals, whether feeding at low trophic levels or on large prey several levels
removed, rely on the distribution of primary production in space and time to organize their foraging strategies.
Diets and foraging behaviors are affected by demographic factors, reproductive status, phylogenetic constraints,
the risk of predation, competitive interactions, and the distribution and abundance of their prey. Much research
remains to be done, but due to the overlap of marine mammal diets with major world fisheries, attention is being
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given to the problem .
Marine mammals have a suite of adaptations for foraging. This is reflected in the dental formulas of each marine
mammal group, particularly pinnipeds. Pinnipeds are heterodont, with specific teeth for specific tasks. Walrus
boast two notable tusks. Otariids have more teeth than phocids. The digestive system corresponds to foraging
strategies as well: pinniped salivary glands are small, the esophagus is muscular and dilatable, the stomach is
simple, they lack an appendix, their liver is large, and the pancreas is elongate. Behaviors complement these
anatomical features, and all are such that energetic cost is minimized. Pinnipeds forage both individually and
cooperatively in groups. Most are pierce feeders, though 3 species are filter feeders of krill. Some, like the
walrus, are benthic feeders. Fish, cephalopods and krill are the most common prey of pinnipeds. Many species
practice seasonal migratory patterns, the most dramatic being the elephant seal who make a double migration
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each year .
Likewise, many trophic levels are exploited by cetaceans as a whole. Odontocetes tend to specialize on prey at
the larger end of the size spectrum, while mysticetes are filter feeders of zooplankton and/or micronekton, using
racks of kerotinous baleen to strain prey-laden water. Tooth-facilitated filter feeding probably occurred in early
mysticetes, which may have incited the evolution of long-distance migrations. Echolocation likely evolved in the
earliest odontocetes, facilitated by changing food resources and oceanographic currents. Mysticetes have been
known to feed in three ways: (1) skimming, (2) engulfment feeding, and (3) suction feeding (gray whales).
Extraordinary skeletal and muscular adaptations enable these feeding modalities. Odontocetes, with their
homodont dentition, feed on larger prey by grasping or suction-feeding (beaked whales in particular perform the
latter). Remarkable social strategies are observed in many odontocete species, but also in some mysticetes
(particularly humpback whales). Cetacean digestive systems are striking in their extreme length. The stomach
has four main compartments; in mysticetes the large intestine has a cecum which is absent in nearly all
odontocetes. Cetacean livers are bi- or triple-lobed. Complementing this feeding equipment are locomotor
behaviors such as annual migrations between high-latitude foraging areas in productive waters and low-latitude
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breeding areas in oligotrophic, warm waters .
Of all marine mammals, only sirenians graze directly on beds of aquatic plants. This is reflected in their
brachyodont teeth, prehensile snout, large salivary glands, and extremely long, fermenting digestive tracts. Sea
otters preferentially feed on benthic invertebrates, and are therefore restricted to shallow habitats. Polar bears
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are massive predators of seals and sometimes walruses .
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Henri Weimerskirch. 2002. Chapter 5: Seabird Demography & its relationship with the marine environment. in Schreiber & Burger 2002.
Henri Weimerskirch. 2002. Chapter 5: Seabird Demography & its relationship with the marine environment. in Schreiber & Burger 2002.
Berta et al. 2006. Ch. 12: Foraging Behavior and Food of Marine Mammals.
Berta et al. 2006. Ch. 12: Foraging Behavior and Food of Marine Mammals.
Berta et al. 2006. Ch. 12: Foraging Behavior and Food of Marine Mammals.
Berta et al. 2006. Ch. 12: Foraging Behavior and Food of Marine Mammals.
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Relative to the terrestrial realm, the marine environment is dynamic in both space and time, particularly with
regards to the biomass at low trophic levels. To deal with this, marine mammals have evolved strategies for
finding their prey (foraging) and capturing it (feeding, such as filter-feeding). Key to a marine mammal foraging
strategy is associating with habitat where prey abundance and availability is high. This is probably the primary
reason that filter-feeding mysticetes migrate between high-latitude foraging areas and low-latitude breeding
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grounds .
Another extraordinary foraging adaptations in odontocetes is echolocation, or biosonar, by which the animal
assesses its environment by emitting sounds and listening to echoes as the sound waves reflect off different
objects in the environment. Echolocation requires a complex head anatomy of multiple tissue layers and waxy,
sound-refracting organs. Sound is produced in the “forehead” by the “monkey lips-dorsal bursae complex”, or
“phonic lips”. Sound reception occurs through the lower jaw, which propagates the sounds to the ear bones.
These echolocation signals are highly directional in the vertical and horizontal planes, and unique frequencies
and click-trains are employed by various species. The detection ranges of echolocation systems are species98
specific .
After prey has been located, feeding strategies are employed to capture it. In odontocetes, homodont teeth are
used for grasping prey. In pinnipeds, heterodont teeth serve multiple purposes, and in two seals and one fur
seal, teeth are used to filter-feed for krill. Sperm whales and beaked whales may employ a suction-feeding
strategy, in which a distensible gular region creates negative pressure in their mouth, sucking in prey. In
mysticetes, baleen structures are used to filter a prey field. The length, number, and coarseness of baleen are
species-specific and correspond to their prey size and foraging strategy. Filter feeding is unique to marine
ecosystems, and is particularly advantageous in large body sizes and in polar regions and coastal upwelling
regions. Balaenids perform a skim-feeding strategy, while rorqual whales employ a unique form of “batch” filter
feeding, or lunge-feeding. Feeding strategy informs other aspects of natural history, such as sociality. Mysticetes
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are typically solitary (with exceptions), while odontocetes can employ highly complex social structures .
Seabirds: It is challenging for air-breathing seabirds to subsist at sea. Seabirds forage on a variety of prey, at a
variety of trophic levels, in a variety of ways. Seabird diets usually consist of a specialized range of taxa, usually
one of three main types of prey: small pelagic fishes, crustaceans, and mollusks. Energy obtained from this food
can be used for basic metabolism, growth, or reproduction, all of which are generally lower in seabirds. Energy
therefore represents the limiting factor in seabird survival. Morphology, especially wing shape and size,
functions to maximize energy uptake in the phylogenetic, oceanographic, and ecological conditions to each
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seabird group .
Oceanographic features, such as turbidity, the depth and temporal stability of the pycnocline, the relative
geography of winds and thermohaline forcing and consequent rate of upwelling and current convergence, etc.,
all serve to determine the local and global distribution of seabirds. Foraging seabirds aggregate in areas of
reliably high prey availability, and are influenced by climatic oscillations such as ENSO. The relationship
between seabird predators and their marine prey appears to be scale-dependent; the relationships seems to
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break down at small spatial scales, suggesting that seabirds sample prey randomly at close-range .
In addition to the form and function of seabirds, evolution has produced adaptive foraging behaviors in them.
Most seabirds forage diurnally, and in some this is associated with the daily vertical migration of their prey. Most
nocturnal foragers are offshore, squid-eating, and occurring in the southern tropical oceans. The foraging range
of birds differs markedly between non-breeding and breeding seasons (in the latter, they are central-place
foragers). Many species are known to use olfaction to detect their prey, approaching slicks from downwind and
flying in a zig-zag pattern. Most seabirds forage-flock after individuals have honed in on a good prey field.
Commensal foraging, usually with cetaceans, pinnipeds, and other subsurface predators like tuna, is also known
to occur. Some species, such as frigatebirds, practice kleptoparasitism (food theft). All of these foraging skills
97 Ballance, L. 2013. Foraging & feeding: marine mammals. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 5.
Ballance, L. 2013. Foraging & feeding: marine mammals. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 5.
Ballance, L. 2013. Foraging & feeding: marine mammals. Marine Tetrapods, Scripps Institution of Oceanography. Lecture, Week 5.
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Schreiber, Chapter 6: Foraging Behavior and Food of Seabirds.
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Schreiber, Chapter 6: Foraging Behavior and Food of Seabirds.
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are presumably acquired gradually by most seabird species, aided by a protracted period of parental care during
which time information transfer may occur. Studies show that adults are more proficient at foraging than
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immatures .
Seabird diet is not static in space or time, and some species show more foraging plasticity than others. Methods
for studying seabird diets include looking at regurgitations, prey dropped near nest sites, prey carried in the bill,
stable isotope analysis. Most information we have on seabird is limited to the breeding season, when birds are
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at their colony .
Our study of seabird foraging behavior is in its infancy. Recent studies are challenging the paradigm of energy
limitation as the governing constraint on seabird natural history, and more studies are needed to disclose the
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complexity of their foraging strategies .
Ecology
Marine tetrapods, especially whales, are relatively enormous members of the ocean ecosystem. By sheer
tonnage, we know that their role in ecosystem regulation must be important, though now it is only a fraction of
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what it was before whaling . “As population numbers grow, so too will the roles they play in the ecosystem”
Thinking strictly in terms of trophic interactions, whales participate in the ecosystem as consumers, as
competitors, and as prey. These three roles are readily seen in a closer look at studies of the Southern Ocean
Ecosystem.
The premise that whaling altered marine ecosystems is not debated by cetologists; whales remove huge
amounts of prey biomass, thus impacting other predators; they may drive evolutionary responses of their prey,
and they have the potential to restructure food webs. However, the ways in which this has played out is difficult
to pin down. Trophic cascades have been observed in studies of marine predator assemblages including
cetaceans on shorter-terms and smaller spatial scales, but more studies aimed at directly observing ecosystem
regulation are sorely needed. The difficulties of answering these questions are compounded by the extensive
and various perturbations to marine ecosystems. The inherent complexity of ecosystem-level questions and the
long history of human interaction with the ocean make it impossible to assess the impact of marine tetrapods on
their environment.
“Attention should be focused now on way to improve our understanding of top-down oceanography (predatorprey interactions at all trophic levels, particularly high levels); how marine community structure and dynamics
are influenced by those processes; and how ecosystems in their dramatically altered condition today behave in
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response to environmental change.”
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Schreiber, Chapter 6: Foraging Behavior and Food of Seabirds.
Schreiber, Chapter 6: Foraging Behavior and Food of Seabirds.
Schreiber, Chapter 6: Foraging Behavior and Food of Seabirds.
Barlow et al. 2008.
Springer et al. 2006
Springer et al. 2006
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Marine mammals of the Kitimat Fjord System
Below is a list and brief synopsis of the natural history of the marine mammals (then a section for seabirds)
expected in the Kitimat Fjord System. Focus is given to those species the Bangarang expects to encounter on
transects.
One of the marine tetrapod groups that I do not cover thoroughly here is reptiles. The only marine reptile
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expected in British Columbia is the leatherback sea turtle, listed as Endangered under Schedule 1 of SARA .
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Leatherback sea turtles have been seen 126 times since 1931 (to 2009) . Areas of the KFS have been
identified as low, medium, and high suitability foraging habitat for leatherbacks. The high suitability areas occur
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in Caamano Sound . No reported sightings have ever occurred in KFS . Leatherbacks feed on scyphozoan
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jellies .
Most of the terrestrial carnivores in the Kitimat Fjord System obtain some or most of their food from the sea. This
includes coastal timber wolves, grizzly bears, black bears (including the white “Spirit” morph), wolverines and
Sasquatch. As a result they could be argued to qualify as “marine”, but this Backgrounder will not cover them
(see the Natural History of the KFS Backgrounder).
Toothed cetaceans
Dall’s porpoise
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Phocoenoides dalli
This porpoise looks like a drunk kid tried to draw a dolphin but changed his mind halfway through and tried to
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draw panda instead. Tiny head, big body. Strongly keeled peduncle above and below . “Thought to be the
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fastest of the small cetaceans.”
“Their blubber is thin for a cold-water species, so they must maintain a
relatively high metabolic rate and thus a high and regular caloric intake.”
“The sexual dimorphism in body size and shape, and the smallness of the testes, suggest that male Dall’s
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Porpoises compete for exclusive access to females” .
The dalli-type subspecies occurs throughout the species’ range. Have a preference for deep (more than 180m),
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cool waters. The truei subspecies does not occur in BC – only the dally-type .
“Dall’s porpoise is widely distributed and commonly observed in deep coastal waters of BC (Williams and
Thomas 2007). There are over 1,000,000 Dall’s porpoises in the North Pacific; however, the abundance in BC
waters is not known (Ford and Olesiuk 2010). In 2004 and 2005, surveys conducted in inside BC waters
resulted in estimates of 4 910 (95% confidence interval: 2 700-8 940) Dall’s porpoises (Willams and Thomas
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2007).” Willams & Thoma (2007) saw Dall’s porpoise most commonly in the offshore waters of Queen
Charlotte Bain and relatively infrequently in mainland inlets.
Mainly eat schooling fish (herring, pilchards, hake) and squid. A high proportion of its diet consists of deepwater,
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vertically migrating species . “Information on the diet of Dall’s porpoises is based on stomach content
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DFO 2014.
DFO 2014.
DFO 2014.
DFO 2014.
DFO 2014.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
20
collection and opportunistically collected carcasses from strandings or bycatch. Opportunistically collected
porpoises from individual strandings or incidental captures during 1990-1997 primarily off eastern Vancouver
Island were sampled and their stomach contents were examined (Walker et al. 1998). In these samples, fish
comprised 99% of the number of prey consumed by Dall’s porpoises. The primary fish prey consumed was
blackbelly eelpout, representing 96.2% of all prey consumed. Other fish species included Pacific herring,
eulachon, walleye pollock, Pacific hake, and Pacific sand lance (Walker et al. 1998). Prey species found in
stranded Dall’s porpoises in southern BC contained primarily squid, Pacific herring, walleye Pollock, sculpins,
myctophids, Pacific hake, polychaetes and bathylagidae (Ford and Olesiuk 2010).”
“A fetus taken from a dead Dall’s Porpoise in British Columbia was deteremined (through DNA sequencing) to
have been fathered by a Harbor Porpoise. This discovery offers a possible explanation for the atypically
pigmented porpoises occasionally seen swimming with and behaving like Dall’s Porpoises around southern
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Vancouver Island and elsewhere.”
Taken for meat in Japan
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. The greatest known threat is the Japan hunt. There than 40,000 were killed in 1988.
Harbor porpoise
Phocoena phocoena
Coastal, often found in fjords, bays, estuaries and harbors. Limited to northern temperate and subarctic
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waters . Distribution is generally discontinuous, resulting in numerous geographical populations. North Pacific
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and North Atlantic populations are entirely separate . Willams & Thoma (2007) saw harbor porpoise most
commonly in the southern straits, but also frequently in mainland inlets and Queen Charlotte Basin.
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Much smaller than other cetaceans in the northern hemisphere, easy to identify . Difficult to approach and
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follow . Generally perceived as solitary and nonsocial . Usually seen alone or in groups of 2-5 . Usually
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feeds individually . Group sizes increase towards the summer . Short-lived, but can make a bunch of babies
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(can be preggers for at least several years in a row) .
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Most of their prey is near the seafloor, but they also forage in water column . Schooling fish less than 16
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inches – herring, capelin, sprat and silver hake form the bulk of the diet . Also eat cephalopods .
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Due to bycatch, has become a species of concern . Certain geographical populations are depleted from
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historical levels. Incidental mortality in fisheries, especially bottom-set gillnets .
Pacific white-sided dolphin
Lagenorhynchys obliquidens
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The only members of this genus in the North Pacific . Most field researchers refer to them as “lags”. .
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Occupy the entire North Pacific . Abundant and gregarious . Schools of thousands are occasionally seen .
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Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
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Close to 1 million individuals in the North Pacific . “Very little information exists on the abundance trends of
Pacific white-sided dolphins in BC waters. Pacific white-sided dolphins were rarely seen in nearshore BC
waters, until the mid- 1980s. They returned to BC waters after an unknown period of absence (Morton 2000).
Aerial surveys were conducted in 2004 and 2005 and counts adjusted to account for detection errors. Their
abundance in BC waters in 2004-2005 was estimated as 25 906 animals (95% confidence interval: 12 872-52
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138 ).” Willams & Thoma (2007) saw lags most frequently in Queen Charlotte Basin, but also in Johnstone
Strait and occasionally in the southern straits.
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Often seen in mixed-species aggregations with other cetaceans, pinnipeds and seabirds . They have a
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particular association with Northern Right Whale dolphins and Risso’s dolphin . They seem to practice an
inshore-offshore rather than north-south seasonal migration in the NE Pacific. “Numbers clearly increase in the
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Inside Passage of British Columbia during winter months, suggesting an onshore movement in that season.”
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Versatile and opportunistic feeder . Diet includes herring, anchovies, capelin, sardines, are important prey in
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“relatively shallow inshore waters of British Columbia . “Heise (1997) found Pacific white-sided dolphins
feeding on Pacific herring, salmon (pink, sockeye, and chum), Pacific cod, shrimp, and capelin. Morton (2000)
found Pacific white-sided dolphins in the Broughton Archipelago feeding on Pacific herring and capelin, with
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indications that they may have fed on Pacific sardine and eulachon, during 1989-1998.”
When foraging during daytime, “they can be seen working cooperatively to corral a tightly balled school of fish,
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often with seabirds in attendance.”
Not considered deep divers; so preying on deep scattering layer species
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probably takes place at night .
Transient killer whales chomp them
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.
Killer whale
Orcinus orca
Killer whales are fucking awesome. They are the largest, most powerful apex predator on earth. Even T. rex
wears killer whale pajamas. They are the most widely distributed whale on the planet. Scholars maintain that
killer whales can even touch MC Hammer. Recent molecular work is likely to reveal several different species
and subspecies of killer whales, but for now the species is divided into ecotypes, or ecologically distinct groups.
Ecotype differentiation is thought to occur in highly productive areas, in which predators can afford to partition
the prey field and specialize their hunting behavior around a particular diet. Conversely, generalist ecotypes tend
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to occur in low-latitude oligotrophic regions .
Killer whales are long-lived (80-100 years) and highly social, exhibiting kin selection, cooperative foraging, food
sharing, and cultural transmission. The species is strongly sexually dimorphic due to the fact that cumbersome
body size is sexually selected for in males. Even as an adult such “trophy sons” are highly dependent on their
mothers, and killer whales travel in family groups of related daughters and sons (matrilines) led by a matriarch.
Sociality and group hunting has led to the evolution of vocal complexity and intelligence in killer whales; one
disputed study reports that a captive killer whale counted to infinity -- twice.
Most information we have regarding their life history come from the Pacific northwest, where there are three
sympatric ecotypes with specialized diets: “residents” (large social groups, vocal, fish-eaters), “offshores” (large
142
Reeves et al. 2002.
Williams and Thomas 2007
From Schweigert et al. 2012 Eulachon Stock Assessment
145
Reeves et al. 2002.
146
Reeves et al. 2002.
147
Reeves et al. 2002.
148
Reeves et al. 2002.
149
Reeves et al. 2002.
150
From Schweigert et al. 2012 Eulachon Stock Assessment
151
Reeves et al. 2002.
152
Reeves et al. 2002.
153
Reeves et al. 2002.
154
Pitman, RL, and J Durban. 2013. The Family that Preys Together: killer whale studies in Antarctic waters. Marine Tetrapods, Scripps
Institution of Oceanography. Lecture, Week 8.
143
144
22
social groups, far-ranging, shark-eaters), and Biggs killer whales (or “transients”, near-silent, smaller family
groups, marine mammal eaters), who are excellent hunters. They say Death once had a near-Transient
155
experience. Recent evidence suggests that Transients may be the reason Waldo is hiding . The Soviet Union
once attempted whaling transient killer whales, and look what happened to them. Ghosts sit around the campfire
and tell transient killer whale stories. When the boogeyman goes to sleep at night, he checks his closet for
156
transient killer whales .
As the top predator of marine ecosystems, killer whales exert remarkable control over the biological structure of
the ocean. For example, the risk of killer whale predation may be a reason for the long-range migrations of
baleen whales, and prey-switching between marine mammal targets may have triggered trophic cascades in the
northeast Pacific. There are no endangered species; there is only a list of animals that killer whales don’t
157
respect .
In Caamano Sound/Gil Island area: “Killer whales take 3 to 8 days to travel between the Johnstone Strait area
and Caamano Sound. They travel between the two areas throughout the year but more commonly between May
158
and October” . “Of the three distinct clans that comprise the NRKW population, members of the A-clan were
the most frequently detected whales, present on 86 percent of all detection days, followed by G and R clan
accounting for 25 and 11 percent respectively. Whales from all three clans were detected in all years. Whales
from all 16 NRKW pods were detected over the study period and members from an average of 11 out of 16 pods
were detected per season (range 8 to 15). The A1, A4, and A5 pods were most frequently encountered. Days of
detection for each of the 16 NRKW pods and generalized pod categories are summarized in Figure 10.
Matrilines identified over the study period visually or through photo-ID are summarized in Table 1. All R-Clan
matrilines, nearly all A-clan matrilines, and various G-clan matrilines have been documented, representing
nearly the entire NRKW population.”
“The primary behaviours observed in the region are foraging, resting, travelling, socializing, and kelp rubbing.
Beach rubbing, an activity NRKW are commonly observed engaging in around Johnstone Strait (Ford, Ellis,
Balcomb, 2000), has yet to be observed in this region.”
The main preference of northern resident killer whales within the Kitimat Fjord System is chinook (spring)
salmon (Oncorhynchus tshawytsha; Ford et al. 1998). “Foraging is commonly observed throughout the study
area from Caamano Sound to Douglas Channel, in all waterways and distances from shore; however, it is
evident that certain areas are used more frequently and at higher intensities than others. A map identifying
important foraging areas was created (Figure 11) based on NCCS observations and local knowledge since 2001
as well as taking into account information from credible third parties (eg. commercial fishers, Gitgaʼat First
Nation, and sport fishers). NRKW are frequently observed foraging intensely along most of the shoreline habitat
from Kiskosh Inlet (lower Douglas Channel) to Caamano Sound. Very little to no effort has taken place north of
Kiskosh Inlet. Foraging also takes place commonly away from the shoreline in open water in Squally Channel,
Campania Sound and Caamano Sound. Areas with very notable foraging activity are located in the Southwest
portions of Caamano Sound around Rennison Island, Beauchemin Channel, and Aristazabal Island extending
northward across the entrance of Caamano Sound to Dupont Island and the Estevan Group, including Estevan
Sound and the southwest and southeast shorelines of Campania Island. The shoreline of Princess Royal Island
from Ashdown Island to McPhee Point located south of Surf Inlet is also of importance for foraging. Foraging in
the center of Caamano Sound is also routinely observed. Around Gil Island, areas of notable foraging activity
occur at the eastern entrance to Otter Channel around Mcreight Point and Fanny Point; the northern end of Gil
Island (Turtle and BlackFly Points), throughout Lewis Pass to Macdonald Bay (on Gil shore); the waters of
Squally Channel between Fawcett Point, Asdown Island, and Campania Island extending to Alexander Island at
the southern tip of Campania Island; the waters surrounding Ashdown Island, and the entire of Whale Channel.
The southern portion of the Estevan Group from Macdonald Island to Dupont Island is of suspected importance
for foraging.”
155
Pitman, RL, and J Durban. 2013. The Family that Preys Together: killer whale studies in Antarctic waters. Marine Tetrapods, Scripps
Institution of Oceanography. Lecture, Week 8.
Pitman, RL, and J Durban. 2013. The Family that Preys Together: killer whale studies in Antarctic waters. Marine Tetrapods, Scripps
Institution of Oceanography. Lecture, Week 8.
157
Pitman, RL, and J Durban. 2013. The Family that Preys Together: killer whale studies in Antarctic waters. Marine Tetrapods, Scripps
Institution of Oceanography. Lecture, Week 8.
158
Pilkington et al. 2012.
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23
Mustached cetaceans
Seven mysticete species occur in the Canadian Pacific waters: minke, gray, blue, fin, humpback, sei and the
North Pacific right whale.159 Of these, fin and humpback are the only mysticetes common in the Kitimat Fjord
160
System. One sei whale was caught in Caamano Sound by the Rose Harbour whalers , and it would not be
surprising if minke whales were visitants to the area. A disputed gray whale sighting occurred in Whale Channel
in 2013, foraging at the mouth of a river. Gray whale migration route from Vancouver Island to Southeast Alaska
161
has long been uncertain , but it has recently been discovered that most gray whales migrate through Hecate
Strait and Dixon Entrance, exposing them to a wider range of industrial activities and developments than they
162
would by migrating along the outer coast .
Humpback whale
Megaptera novaeangliae
“Humpback whales migrate to BC waters to forage during the spring and fall. Capture-recapture techniques,
combined with a photo-identification program to identify individual whales, were utilized to estimate the
abundance of humpback whales. Ford et al. (2009) estimated a bias-reduced abundance of humpback whales
in BC waters during 1992-2005 using photograph records from May to October, 1984-2006. Ford et al. (2009)
estimated that the humpback whale population in BC waters increased at a rate of 4.1% annually since 1992
(Ford et al. 2009; Figure A2-6). In 2006, it was estimated 2 145 humpback whales occupied BC waters in the
spring and fall, which is lower than the estimated 4 000 animals thought to occupy BC waters in the early 1900s,
prior to large-scale commercial whaling (Ford et al. 2009). The increase in humpback whale abundance is likely
163
due to the recovery from whaling; legal whaling ended in 1966 (Ford et al. 2009).”
164
North Pacific whaling brought the region’s humpback whale population down from ~15,000 to 1,400 whales .
165
The last humpback whale killed by BC whalers was in 1965 . The population(s) has since recovered with great
166
success. Approximately 21,808 animals in the North Pacific as a whole , which has raised the question of
whether humpbacks are at or above historical carrying capacity and should still be protected as if they are
depleted. In areas of high density humpbacks are known to maintain a distance from each other, which may
167
determine the number of animals that can occupy aggregation areas where space is limited .
159
160
161
162
163
164
165
166
167
Nichol and Ford (2011).
Nichol et al. 2002
Ford et al. 2013.
Ford et al. 2013.
From Schweigert et al. 2012 Eulachon Stock Assessment
Barlow et al. 2011, Calambokidis & Barlow 2004.
Nichol et al. 2002.
Barlow et al. 2011.
Braithwaite et al. 2012.
24
The whales that feed in BC spend their winters in a number of mating and calving grounds, including Hawaii,
168
Mexico and Japan . Willams & Thomas (2007) saw humpbacks most frequently in Queen Charlotte Basin and
the mainland inlets of the north and central coasts. DFO has identified four critical habitat areas for humpbacks
in BC: 1) Waters surrounding Langara Island, 2) coastal waters of Moresby and Kunghit Island, 2) mainland
channels around Gil and Gribbel Island, and 4) waters off southwest Vancouver Island including Barkley Sound,
169
La Perouse Bank, Swiftsure Bank and Barkley Canyon . “Low rates of inter-matches between areas suggest
170
the four areas support, to a large extent, different parts of the population.”
171
172
173
168
169
170
171
172
173
174
Fisheries and Oceans Canada (2010)
Nichol et al. 2010.
Nichol et al. 2010.
Nichol et al. 2010.
Nichol et al. 2010.
Nichol et al. 2010.
Nichol et al. 2010.
25
174
“Humpback whales consume large zooplankton and schooling fish. Euphausiids comprise the majority of prey
items consumed by humpback whales (Ford et al. 2009) but proportions of their prey types likely vary spatially
and temporally, depending upon availability. Fish prey includes Pacific herring, mackerel, sand lance, Pacific
sardines, anchovies, and capelin (Ford et al. 2009). Witteveen et al. (2006) suggested that humpback whales
consumed fish in proportion to those available in the water column, as sampled with a midwater trawl, where
whales were actively feeding. The majority (>90%) of the pelagic fish biomass sampled by a pelagic trawl off the
WCVI includes Pacific herring, Pacific hake, Pacific sardine, chinook salmon, and spiny dogfish (Tanasichuk et
al. 1991; Ware and McFarlane 1995; Robinson 1994; McFarlane and Beamish 2001). There is no direct
evidence that humpback whales consume eulachon, but if they co-occur with eulachon, it is likely they could
175
consume some.”
Humpbacks in B.C. and Gulf of Alaska waters have been observed feeding upon sardine, herring, capelin,
pollock, eulachon, Pacific mackerel (Scomber japonicas), and euphausiids (Nemoto 1959, Fisheries & Oceans
Canada 2010). Stomach content records (summarized by Ford et al. 2009) were dominated by the euphausiids
E. pacifica and T. spinifera. One stomach was found to contain a species of small squid (Ford et al. 2009).
Pacific hake (Merlucius productus) is also dominantly abundant in coastal waters (Mackas et al. 1997) and may
be preyed upon by humpbacks. Relative to the specialized diets of other rorquals, humpback whales forage
opportunistically (Calkins 1986).
DFO has observed the following: Humpbacks “feeding on schooling fish was considerably more common than
demonstrated in the whaling records, particularly in nearshore waters. Fish species observed to be taken by
humpbacks in coastal waters include Pacific herring (Clupea pallasi), Pacific sand lance (Ammodyes
hexapterus), and Pacific sardine (Sardinops sagax). However, no recent studies have yet been undertaken to
176
document the degree of whale foraging on these prey species in BC waters .
From previous experience in the study area, the author can attest that humpback whales are bubble-net feeding
intensively on schooling fish – almost definitely herring -- in early and mid-summer. There is a marked change in
their feeding behavior later in the summer (Keen et al., unpubl. data), suggesting that humpbacks switch to a
krill-dominated diet in the late summer (Janie Wray, pers. comm.). It has been suggested elsewhere that
humpbacks can prey switch between years (Krieger & Wing 1985).
Just north of the study area in Fredericka Sound, AK, the euphausiids T. raschi and E. pacifica constitute 5080% of humpback diet (Dolphin 1987). T. longipes have also been found in stomachs in the Gulf of Alaska,
sometimes hundreds of kilograms of the species (Tomilin 1957, in Russian; cited in Calkins 1986). Euphausiid
patches consisting of high concentrations of T raschi were more likely to be humpback prey than those patches
with relatively less T raschi (Dehalt 1985). Dolphin (1988) wrote: “The primary prey species of the humpback
whales in southeast Alaska have been identified as the euphausiid crustaceans Thysanoessa raschi (Dolphin
1987c; Wing and Krieger 1983), Thysanoessa longipes (Wing and Krieger 1983); Bryant et al 1981),
Thysanoessa spinifera (Nemoto and Kasuya 1965; Bryant et al. 1981; Wing and Krieger 1983), Euphausia
pacifica (Jurasz and Jurasz 1979; Bryant et al. 1981; Wing and Krieger 1983), and the fishes Pacific herring,
Clupea harengus (Jurasz and Jurasz 1979; Wing and Krieger 1983), capelin, Mallotus villosus (Jurasz and
Jurasz 1979; Wing and Krieger 1983), Pacific sand lance, Ammodytes hexapterus, and juvenile walleye
pollock, Theragra chalcongramma (Dolphin 1988), based on stomach contents, analysis of fecal samples, and
visual observation of feeding.”
Gil Island humpbacks: The most current (2011) estimate of abundance of humpback whales that use the Gil
Island area in summer months is 137 (120-153 CI95%), representing 6-8% of the BC humpback whale
177
population . The photo-ID records of North Coast Cetacean Society and the Gitga’at First Nation demonstrate
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high inter-annual site fidelity to the area .
175
176
177
178
From Schweigert et al. 2012 Eulachon Stock Assessment
Nichol et al. 2010.
Ashe et al. 2013
Ashe et al. 2013
26
179
“The Gil Island area is the only fjord habitat identified as candidate Critical Habitat.”
“This area is quite
180
distinctive as the only fjord-like habitat area recommended for as Critical Habitat.”
“The earliest reported
humpback sighting in the Gil Island area since the end of the whaling era dates from 1992 (BCCSN unpubl.
data). Since 2002, there has been a significant increase in data collection and monitoring efforts in this area as a
result of DFO ship-based surveys, the presence of the Northcoast Cetacean Society (NCCS) on Gil Island, and
181
Gitga’at Lands and Resources Stewardship Society (GLRSS) small boat surveys.”
“The first Humpback
Whales photographically identified from this region date from August and October 1997… More photo-IDs per
encounter day have been obtained July through October than in other months. Ford et al. (2009) noted that in
182
general the presence of whales in the mainland inlets in B.C. is greatest from late summer through fall.”
Fin whale
The natural history of fin whales in the Kitimat Fjord System is covered in its own Backgrounder.
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180
181
182
Nichol et al. 2010.
Nichol et al. 2010.
Nichol et al. 2010.
Nichol et al. 2010.
27
Pinnipeds
Harbor seal
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Phoca vitulina
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Harbor seals occur in both the Atlantic and Pacific in the northern hemisphere . May number 500,000 or more
185
186
187
throughout their range . There are five recognized subspecies . Variable pelage with latitude . In the north
Pacific, dark pelage is more common in the southern areas, whereas light and intermediate morphs predominate
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189
in northern areas . Solitary when at sea. Rather curious . “Harbor seals are generally intolerant of close
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191
192
contact with other seals.” The least vocal of all pinnipeds . Serially monogamous . “Unusually precocial for
pinnipeds, harbor seal pips are able to swim and dive within minutes of birth.. In the water, they often ride on
193
their mother’s backs by holding on with their fore-flippers.”
In the Gulf of Alaska pupping occurs in May/June and molting occurs during August/September, when haul out
194
rates peak . Harbor seals haul out in greatest numbers during mid-day, though this varies fro region to
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196
197
region . There are also haul out peaks at low tide , and there are more seals in water during rain .
“Harbour seals are year-round residents of coastal BC waters (DFO 2010b). They are primarily distributed within
20 km of shore and enter some rivers, such as the Skeena and Fraser Rivers (DFO 2010b). They typically
forage within 10-20 km of haul-out sites and demonstrate high site-fidelity (DFO 2010b). Estimates of
abundance of the harbour seal population in BC is estimated using standardized counts of animals at haul-out
sites. Surveys to determine trends have been conducted in the Strait of Georgia (Figure A2-5, top panel) and in
representative areas (index areas) distributed throughout B.C. (Figure A2-5, bottom panel). Corrections are
198
applied to account for animals at sea and missed during surveys.” Willams & Thomas (2007) saw harbor
seals everywhere; they were the most commonly sighted marine mammal in their two summers of surveys.
“Overall, harbour seals in BC have increased ten-fold since the 1970s, with an estimated total of 105 000
animals currently inhabiting coastal waters (DFO 2010b). The harbour seal population increase is due to the
recovery of the population, which had been severely depleted by over-hunting prior to their protection in 1970
(DFO 2010b). The population growth rate appears to have stabilized suggesting the population has reached
199
carrying capacity at near-historic levels (DFO 2010b).”
“Harbor seals forage in a variety of marine habitats, including deep fjords, coastal lagoons and estuaries, and
200
high-energy, rocky coastal areas.”
Highly diverse diet, including demesreal fish, pelagic schooling fish,
201
octopus and squid, depending on availability.
“Harbour seal diet information is available primarily for the
Strait of Georgia (SOG) (Olesiuk et al. 1990, Olesiuk 1993). In the SOG and its estuaries, harbour seal diet
varies seasonally but is generally comprised of small- to medium-sized schooling fish, such as hake and herring
(Olesiuk et al. 1990, DFO 2010b). Smelts (mainly eulachon) were found to be consumed incidentally and in
small quantities (Olesiuk et al. 1990). Eulachon represented about 0.4% (range 0.3 % and 1.8% of seal diets in
1988, which, given certain assumptions of harbour seal energetic requirements, suggests harbour seals in the
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SOG consumed between 23 and 149 t of eulachon annually in 1988 (Olesiuk 1993).” Sand lance was the
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184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Boveng et al. 2003.
Boveng et al. 2003.
Boveng et al. 2003.
Boveng et al. 2003.
From Schweigert et al. 2012 Eulachon Stock Assessment
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
28
203
most frequently identified prey item of harbor seals in the bays of Oregon , where many benthic and epibenthic
204
205
fish are important to harbor seals . They are also known to target salmon, particularly chum .
Harbor seals are still killed legally in Canada, Norway, and the UK to protect fish farms or local fisheries
206
.
Steller sea lion
Eumetopias jubatus
Named after Wilhelm Steller, the German surgeon and naturalist who described sea lions he encountered while
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208
shipwrecked . Also known as the Northern sea lion. This is the largest otariid and the only sea lions that
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210
occur in the Bering Sea and the Gulf of Alaska . Well-developed forehead (what genus name means) . Their
211
range extends as far south as Southern California .
Compared to California sea lions, Steller sea lions are substantially larger, with a more robust head and a
212
broader snout, and males are tan to blond with a conspicuous mane on the neck Most of their dives last less
213
than one minute .
“Steller sea lions are year-round residents of BC waters. Breeding animals spend the spring and summer on
breeding sites (DFO 2010a; Olesiuk 2008). Territorial males fast during breeding season and females spend a
week with newborn pups before making foraging trips. In August- September, breeding animals disperse from
rookeries and occupy winter haul-out sites in protected waters and intermingle with California sea lions (DFO
2010a). Non-breeding animals are found at year-round haul-out sites on the outer, exposed coast (DFO
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2010a).”
While abundance has greatly declined across the species’ range, from several hundred thousand in the 1970s
215
to about 60-70,000 in the late 1990s , populations in BC waters have incrased. “Province-wide aerial surveys
are conducted approximately every four years at the end of breeding season to provide an estimate of pup
production and counts of juveniles and adults (DFO 2008). Survey counts provide minimum estimates of juvenile
and adult abundances and an indicator of population trends, during 1971-2010. Survey counts indicate that local
breeding populations of Steller sea lions in BC and SE Alaska have been increasing at a rate of 3-4% per year
(DFO 2010a) since the mid- 1960s (Figure A2-4). Pup counts also have increased since the mid-1960s (DFO
2008). Applying corrections to account for animals at sea and missed during surveys, abundance of Steller sea
lions in BC waters during the summer breeding season in 2010 was estimated as 31,900 animals, with 22% in
the Fraser DU, 46% in the Central DU, and 32% in the North DU. Based on winter surveys, abundance outside
the breeding season in 2010 was estimated as 48,000 animals, with 30% in the Fraser DU, 29% in the Central
DU, and 41% in the North DU (DFO 2010a). The seasonal increase during winter is due to the influx of animals
from neighbouring rookeries in SE Alaska and Oregon. The increase in Steller sea lion abundance is partly
attributable to recovery from hunting and predator-control programs, but in recent years populations have
216
exceeded peak historic levels.”
217
“Steller sea lions are presumed to forage mostly close to continental and island coastlines” . “During the
summer breeding season, the Steller sea lions prey on forage fish (mainly herring, sand lance and sardine),
gadids (mainly hake), salmon, rockfish, flatfish and other prey (Trites, A. and Olesiuk, P.F., unpubl. data). Based
on SSFO, eulachon comprised less than 0.1% of the summer diet in BC and SE Alaska. During the non-
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204
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206
207
208
209
210
211
212
213
214
215
216
217
Brown et al. 1983.
Brown et al. 1983.
Brown et al. 1983.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
29
breeding season, primary prey includes forage fish (mainly Pacific herring and sardine), gadids (mainly Pacific
hake and walleye pollock), dogfish, salmon, squid and octopus, eulachon, sandlance, and lingcod (Olesiuk and
Bigg 1988). With the exception of Sand Heads, where both California and Steller sea lions congregate when
218
eulachon are spawning, eulachon otherwise constitute <0.1% of the winter diet.”
219
Protected by the Canadian Fisheries Act .
Another good source:
Bigg, MA. 1985. Status of the Stellar sea lion (Eumetopias jubatus) and California sea lion (Zalophus
californianus) in British Columbia. Can. Spec. Publ. Fish. Aquat. Sci. 77, 20 pp.
220
California sea lion
221
Zalophus californianus
222
These are the bottlenose dolphins of the pinnipeds. Easily trained and often seen in zoos and aquaria . Rarely
223
224
seen north of Vancouver Island . Slender-bodied , though males are bulky at the neck and breast but very
225
226
slender on the hind end . Adult males are mostly dark brown to black, with areas of light tan on face .
227
Only spend several days to two weeks at sea . In the summer females dive to 245 feet for about four minutes.
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229
Dive become deeper over the course of the year . Maximum recorded depth is 536m, 12 minutes .
California sea lion populations have increased at least fourfold since the 1970s when the MMPA came into
230
231
effect . Mainly the males migrate north into British Columbia waters . “Adult and sub-adult male California
sea lions began to appear in BC waters in the 1960s. Animals occur during the non-breeding season primarily
off southern Vancouver Island (approximately 240 days; Hancock, 1970; Bigg, 1985). Winter survey counts are
conducted off southern Vancouver Island to monitor population trends of these animals in BC waters. California
sea lion counts in BC waters increased from a few hundred animals in the 1970s to 1500 in the 1980s (Bigg
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219
220
221
222
223
224
225
226
227
228
229
230
231
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
30
1985; Figure A2-2). Counts peaked at 4,500 animals in 1984 and then stabilized at approximately 3,000 animals
(Bigg 1985). Since then, the counts have fluctuated from 1 000 to 3 000 animals (P. Olesiuk,DFO, pers. comm.).
Only southern Vancouver Island has been consistently surveyed, as this is where the majority of California sea
lions occur. However, the species has extended its range northwards in recent years, and small numbers now
occur as far north as the Gulf of Alaska. The only province-wide winter surveys were conducted in 2009-2010
and indicated that relatively few California sea lions occur north of the Fraser DU area (76% of the BC total were
232
counted in the Fraser DU, 19% in the Central DU and 5% in the Northern DU).”
233
Diverse diet includes “northern anchovy, market squid, sardines, Pacific and jack mackerel, and rockfish
234
among their favored prey.”
“California sea lions feed in coastal waters compared with offshore fur seals, but
there is considerable overlap in diet (Olesiuk 2009). Scats collected during 1982-1985 indicate California sea
lions in BC feed primarily on Pacific herring (35% of their diet), Pacific hake, walleye pollock, dogfish, and some
salmon (10% of their diet; Olesiuk and Bigg, 1988). Eulachon were consumed in very small proportions (<0.1%
of their diet; Olesiuk and Bigg, 1988; P.Olesiuk, DFO, pers. comm.), with the exception of the mouth of the
Fraser River. California sea lions congregate at the Sand Heads Jetty in April-May (Figure A2-3), and eulachon
235
comprise an important prey item (32% of the diet, P.Olesiuk, DFO, pers. comm.).”
Northern Fur Seasl
Callorhinus ursinus
236
This is one of the two fur seals in the Northern Hemisphere (other is the Galapagos fur seal). The northern fur
seal (Callorhinus ursinus) is the most widely distributed and abundant pinniped in the North Pacific Ocean.
Primary breeding colonies are in the Bering Sea at the Pribilof Islands and the Commander Islands, with smaller
237
colonies on offshore islands from California to the Aleutians . Males leave colonies by September, females by
238
239
240
October . Solitary when foraging at sea.
Polygynous breeders.
241
There are about 1.2 million seals throughout entire range . “Northern fur seals are highly migratory and
approximately 1/3 of the North Pacific population (~375 000 animals) winters off the coast of North America
(DFO 2007). Approximately 1/3 of this overwintering group of animals (~125 000 animals) resides in coastal BC
waters for approximately 3 months at some point during December-May, with a peak abundance in May
(Olesiuk 2009; DFO 2007). Females comprise the majority of animals and their main wintering area in BC is the
242
La Perouse Bank off of the southwest coast of Vancouver Island (DFO 2007).”
“The abundance of northern fur seals in the Pacific has decreased over the last 30 years and is a conservation
concern (DFO 2007). This decrease in the North Pacific population has occurred on the Pribilof Islands, Alaska,
the cause of which is not known. Abundance on other smaller rookeries has been stable or increasing.
Assuming migration patterns have not changed, abundance in BC is probably proportional to pup production,
which has decreased overall (Figure A2-1).”
The species undertakes a large-scale migration from breeding areas typically situated at high latitudes in the
243
Bering Sea and Sea of Okhotsk, to more southerly feeding areas . Fur seals may forage at sea for months,
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some for several years at a time.
Tend to dive at night over the abyss, more daytime over the shelf . Mostly
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shallow dives, 60 to 165 feet, but up to 820 feet . Eats a variety of nearshore pelagic squid and fish.
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From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
From Schweigert et al. 2012 Eulachon Stock Assessment
Olesiuk 2012.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
31
“Stomach contents collected during 1958-74 indicate that fur seals in the La Perouse Bank core area were
feeding predominately on herring (Figure 14), a high-energy forage fish (Perez and Bigg 1986). Other prey
consumed in lesser quantities included salmon, sticklebacks, rockfish, squid, sablefish, eulachon, anchovy,
248
shad, and hake.”
“Northern fur seal diet varies by season and region, but stomach samples collected during
1958- 74 indicated that overwintering animals in BC waters primarily forage on Pacific herring and squid (DFO
2007, Perez and Bigg 1986). Other important prey items noted in stomach samples at various times and
locations during January-June, 1958-1974 included walleye pollock, sablefish, and salmonids (Perez and Bigg
1986). Eulachon occurred in 33 of 1038 (3.0%) of the stomachs containing prey that were collected off BC, and
comprised 2.3% of the overall diet based on a volumetric basis. Eulachon can be locally and seasonally
249
important prey when they are spawning”
Heavily depleted by sealing
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,
.
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253
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255
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249
250
251
252
253
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Olesiuk 2012.
From Schweigert et al. 2012 Eulachon Stock Assessment
Reeves et al. 2002.
Reeves et al. 2002.
Olesiuk 2012.
Olesiuk 2012.
Olesiuk 2012.
Olesiuk 2012.
32
Northern Elephant Seal
Mirounga angustirostris
Were thought to be extinct in the late 1800s. By 2000, the population may have numbered more than 150,000
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individuals . “Adult male has large inflatable nose.”
The NES breeds in California, but non-breeding foraging
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range (8-10 months of year) is great and includes the KFS . “They are rarely seen at sea because they mostly
forage away from the coast and spend about 80 to 90 percent of their time submerged, usually at great
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depths.”
Most dives are to depths of 1,000 to 2500 feet and last an average of 20-30 minutes. “The deepest recorded
dive, by an adult male, was to 5,141 feet (1,567m), and the logest recorded dive, by an adult female, lasted two
260
hours.
Mostly eat mesopelagic fish and squid. Some seals may forage on the sea bottom at the continental
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shelf for slow-moving skates, rays, sharks and rockfish.
Mustelids
Sea otter
Enhydra lutris
Sea otters recently returned to the Kitimat Fjord System; at least several resident sea otters occur in the
Caamano Sound / Surf Inlet area.
On the mammalian continuum of secondary adaptation to marine living, the otters (Carnivora: Mestelidae:
Lutrinae) fall very near to land. The mustelid lineage dates back to the early Miocene, and it experienced
radiation 11-14 mya, bringing about the three extant lineages. The distribution of sea otters has been confined to
262
the North Pacific Ocean since the Pliocene . Six of the 13 extant otter species are at least partially marine, with
the sea otter of the North Pacific being the only fully marine mustelid. All six inhabit high-latitude coasts, and can
be found in northwestern and northeastern North America, southwest South America, northwestern Europe,
South Africa, and Japanese and Russian coasts near the Okhotsk Sea. All species are confined to the coast,
and individual sea otters usually limit their home range to 20km of coast and can be highly territorial. When local
population density becomes high, the principle mechanism of population regulation in sea otters appears to be
263
pup abandonment and induced starvation in pups .
Relative to other marine mammals, sea otters are small (up to 50kg). Their serpentine body shape, flexible
spine, stout but laterally-flattened tail, flipper-like hind limbs and integral webbing between digits, as well as
incredibly dense pelage (up to one million hairs per square inch), enable their locomotion in water. They must
spend inordinate energies producing and grooming their pelt, the primary method of thermoregulation. This is
compensated with a high metabolism and the use of a specific dynamic activity of digestion for further warmth.
Their large, efficient kidneys aid in osmoregulation, and their large lungs and short, wide trachea enable otters to
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both remain buoyant at the surface and dive as deep as 100m (for as long as 3 minutes) .
Marine-living otters occur at much greater densities than the freshwater otters, a likely result of the superior
productivity of marine coasts. This density difference has manifested itself in divergent mating and social
systems among the species. Marine-living otters tend to specialize on fish, while obligately marine sea otters
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Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
Reeves et al. 2002.
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
33
feed on benthic prey (echinoderms, mollusk, arthropods, up to 150 species), which they bring to the surface for
265
consumption. Both the sea otter and the Cape clawless otter have used tools as aids in foraging .
The semi-aquatic otters link wet and dry ecosystems by transporting nutrients between the two. They are known
266
to select specific sites for latrines that signal social cooperation or territorialism, depending on the population .
Beyond this, the community ecology of semi-aquatic otters are much less studied than sea otters. Sea otters
provide one of the clearest cases of predator-induced effects on trophic cascades and ecosystem function. The
sea otter’s presence in the North Pacific over deep time, during which it kept herbivores of kelp in check, may
267
have structured the evolutionary trajectory of kelp forest systems .
Sea otters have been heavily hunted throughout history, first by aboriginal peoples, then by the Anglo fur trade.
Only a dozen remant colonies were hanging on before protection was enforced in 1911, which reduced genetic
diversity in the surviving population considerably. After a series of re-introductions throughout southeast Alaska,
British Columbia, and the United States west coast, many populations are increasing at rates near their
th
theoretical maximum. The sea otter’s recovery is one of the great success stories of 20 century conservation.
However, some populations have lagged, perhaps due to predation by killer whales who prey-switched from
th
larger marine mammals that were also depleted in the 20 century. They are also particularly vulnerable to oil
spills, and conflict with shellfisheries. Other otter species are still exploited for fur, and the only otter protected
268
internationall is the giant otter of the Amazon .
Sea otters are adorable, but they will bite your face off (PK Dayton, pers. comm.).
Other weasels
River otters (Lontra canadensis) also occur in the Kitimat Fjord System along with smaller common weasels like
mink (Mustela vison) and marten (Martes Americana).
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268
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
J.A. Estes, J.L. Bodkin, and M. Ben-David. 2010. Otters, Marine. Encyclopedia of Marine Mammals.
34
Seabirds of the Kitimat Fjord System
Gaviiformes : Gaviidae : Gavia
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Loons are mainly fish-eating, foot propelled diving birds inhabiting fresh- and saltwater locations . All breed on
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freshwater and are highly migratory . They dive from the surface, usually without springing clear and
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most can reach depths of 75m . All except red-throated require long run to become airborne . From his
d’Etremont’s (2010) surveys in the study area, common and red-throated loons were the most common loons in
the area.
Common Loon – Gavia immer.
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Summer visitant but winters on coast littoral marine waters . In BC there is a large population of nonbreeding birds (presumed to be sexually immature), part of which summers on the coast, both on the sea and on
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freshwater lakes, and part in the interior .
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They also forage on lakes . Swims using legs and feet and often dives to 50m . Prey is usually swallowed
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underwater. “In coastal wintering areas it eats mainly fish, but also crabs and other marine invertebrates.”
Yellow-billed loon – Gavia adamsi
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Scarce winter visitant – not excpected. Three specimens seen in BC as of 1947. . Yellow-billed loons
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occasionally occur near Kitimat
and are known to breed on Banks Island .
Arctic Loon – Gavia arctica
“Known chiefly as an abundant transient, and a winter visitant on the Coast Littoral. Not known to nest in the
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Province.”
Red-throated Loon – Gavia stellate
“Summer visitant to the small lakes situation on island in the northern portion of the Coast Littoral Biotic Area,
and to lakes near the sea on the northern portion of the mainland coast. Winters on the Coast Littoral waters
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adjacent to these regions and southward. Scarce tranisient in the interior.” Unlike other loons, during the
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breeding season red-throated loons travel to saltwater habitats to collect food for its young . Only diver that
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can take off directly from water—all others require a running start
Podicipediformes : Podicipedidae
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All of the North American grebes have been seen in the KFS except for eared grebe and Clark’s grebe .
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Grebes are weak flyers , keeping their neck and head lower than their back in flight. All listed here disperse to
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Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Munro et al. 1947
Munro et al. 1947
Munro et al. 1947
D’Entremont 2010
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Munro et al. 1947
Horwood 1992
D’Entremont 2010
D’Entremont 2010
Munro et al. 1947
Munro et al. 1947
D’Entremont 2010
Harrison 1982
D’Entremont 2010
Harrison 1982
35
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coastal waters in winter . From his d’Etremont’s (2010) surveys in the study area, red-necked and western
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grebes were the most common grebes in the area.
Red-necked grebe – Colymus grisegena
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Largest N. American grebe . “Summer visitant to the interior, less common in the north half of the Province.
One breeding record for the coast on Vancouver Island. Winters on Coast Littoral, less commonly on the coast
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lakes and only occasionally in the interior.” Breeds inland, disperses to coast in winter . Snaps multiple
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animals up during a single foraging dive . Dives are usually 30 seconds but can be more than 2 minutes .
“Diet consists mostly of small fish secies such as eels, minnows and herring. Also takes shrimp, small crab,
prawns and other small marine invertebrates. On its freshwater breeding grounds it takes a wide variety of small
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fish, aquatic insects, other invertebrates and a small amount of plant matter.”
Monogamous pairs breed
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exclusively on freshwater .
Horned grebe – Colymbus auritus
“Summer visitant throughout the Province except in the Coast biotic areas. Winters along all the coast and,
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occasionally, in small numbers on the large lakes of the southern interior.” Wide-ranging . Kicks with its feet
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simultaneously to swim . Dives to shallow depths to capture food -- often a benthic feeder on marine
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wintering range . Dives are usually less than 30 seconds
“Diet on coastal wintering grounds includes a
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variety of small fish, crustaceans, marine worms and other invertebrates.”
Monogamous, breeds only on
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freshwater.
Eared Grebe - Podiceps nigricollis
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Wide-ranging . Breeds inland, winters both inland and along coasts. Gregarious, forms large flocks .
Western grebe – Aechmophorus occidentalis
“An abundant transient across the Province. Winters in large numbers on the Coast Littoral in Georgia Strait and
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occasionally, in small numbers, on Okanagan Lake.” Common visitor to sea coasts during winter.
Eye
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completed surrounded by dark feathers . Colonial; hundreds to thousands at favored localities . “The number
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of western grebes wintering on the north coast is considered very few (Vermeer et al. 1983)” .
Pied-billed grebe – Podilymbus podiceps.
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Pied-billed grebe has only been reported once in the Kitimat area.
“Resident in the Gulf Islands and Puget
Sound …Areas. …A ummer visitant to the interior as far north, at least, as Ootsa Lake. It is the first of the
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grebes to arrive on inland waters inspring; occasionally a few winter on the larger lakes in the south” . Rare on
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ocean .
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Harrison 1982
D’Entremont 2010
Harrison 1982
Munro et al. 1947
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Munro et al. 1947
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Harrison 1982
Harrison 1982
Munro et al. 1947
Harrison 1982
Harrison 1982
Harrison 1982
D’Entremont 2010
D’Entremont 2010
Munro et al. 1947
Harrison 1982
36
Procellariiformes : Procellariidae : Puffinus
Sooty shearwater – Puffinus griseus
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One of the most abundant seabirds in the world -- estimated 20 million individuals . Can live to 30 years .
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“Range overlaps with short-tailed shearwater . Flight normally strong and direct – two to eight quick, stiff324
winged flaps on ascending tack followed by long glide; in higher winds fast and careening . Plunges headfirst
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from about 1m with wings open, submerging for short periods .
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Average maximum depth of dives is 35m . Short plunge dives from 1-3m above water also occur . “While
swimming, it forages by seizing food on the surface or by bill-dipping prey from just beneath the surface of the
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water. Often follows whales to capture the fish they stir up to the surface.” “Diet consists primarily of small
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fish, squid and crustaceans . Must patter along the surface before becoming airborne .
Pink-footed shearwater – Puffinus creatopus
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“A regular but scarce summer visitat to the Pelagic Waters…” “Abundant summer and autumn visitant to the
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Pelagic waters and Coast Littoral Biotic Areas; occasionally common in Georgia Strait.” The pink-footed
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shearwater is seldom seen near shore .
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Flight progressions slow, unhurried, long glides on stiff wings broken by slow effortless flaps . Wings rise and
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fall well above body . “Dives well, also feeds by skimming suface with pink feet extended to tread water
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between shallow belly-flops” . Gregarious at sea .
Short-tailed shearwater – Puffinus tenuirostris
Small numbers move E to western coasts of N America, where uncommon from Washington S to California,
most occurring Nov-Feb. A few non-breeders remain in Alaskan waters throughout winter to 30 degrees
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North .
Procellariiformes : Hydrobatidae : Oceanodrama
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Smallest group of the tube-noses . Northern genera have short legs and usually longer more pointed wings .
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Storm-petrels provide one of the greatest identification challenges (though not in the KFS!) . Flight and feeding
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action are important identification criteria to note down at the time of observation .
Fork-tailed storm petrel – Oceanodroma furcate (plumbea)
“Abundant on the waters of the coast littoral, nesting at scattered points along the west coast of Vancouver
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Island, the Queen Charlotte Islands, and on islands in Queen Charlotte Sound.” O.f. plumbea breeds on
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islands off southern Alaska, WA, OR and Nor Cal. Returns to colonies about ay . Egg dates are June and
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Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Harrison 1982
Harrison 1982
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Munro et al. 1947
Munro et al. 1947
D’Entremont 2010
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
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Harrison 1982
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July . “Contour-hugging flight recalls Leach’s, but not as buoyant or erratic with shallow wingbeats and rather
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stiff-winged glides. In bright sunlight can appear whitish at a distance” . Frequently settles on water, often in
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groups .
Leach’s storm-petrel – Oceanodroma leucorhoa
“Less common than the fork-tailed petrel. Nests on small islands in the Coast Littoral where it probably is
348
resident.”
“Forages on the open ocean by flying slowly or hovering just above the qwater while picking prey from the
surface. Occasionally it dangles its feet and patters the water…Not known to dive. Appears to rely somewhat on
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a keen sense of smell for finding food, a skill that would be especially useful for feeding at night.”
“A wide
variety of small food items found on the ocean’s surface are taken by this opportunistic feeder. Small fish, squid,
octopus and jellyfish, as well as shrimp and other crustaceans, are includd in its diet. Also feeds on the oil left by
the floating carcasses of whale and on whale feces. The petrel converts its food into a rich oil that is stored
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internally for later feeding to its chick.”
Pelecaniformes : Phalacrocoracidae : Phalacrocorax
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Cormorants are underwater-pursuit swimmers . Some reach depths of 30m . They are characterized by
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hooked bills, long necks, elongate bodis, short rather rounded wings and long, normally wedge-shaped tails .
Double-crested cormorant – Phalacrocorax auritus
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Abundant during winter in the Coast Littoral. Relatively scarce in summer. Groups are often seen flying in V
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formation . A dive-pursuit feeder
who brings fish to surface before eating . “Fish are eaten almost
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exclusively.”
Brandt cormorant – Phalacrocorax penicillatus
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Commonest cormorant from Oregon S to California . Status in SE Alaska usually erratic . Common winter
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visitant to the Coast Littoral. Present in summer on the west coast of Vancouver Island where it may rest.
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Habits exclusively marine, restricted to rocky coasts . Flocks flying in extending skeins, feeding and roosting
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together .
Pelagic cormorant – Phalacrocorax pelagicus
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From d’Etremont’s (2010) surveys in the study area, pelagic cormorants were the most common.
A
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subspecies of the Pelagic cormorant (pelagicus) breeds along the BC north coast and is red-listed . Pelagic
cormorants are year-round residents in the study area, whereas Double-crested and Brandt’s occur as non366
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breeding winter visitors . Smallest west coast cormorant . Resident or winter visitant along the entire coast of
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Harrison 1982
Harrison 1982
Harrison 1982
Munro et al. 1947
Leslie, S. 2008.
Leslie, S. 2008.
Harrison 1982
Harrison 1982
Harrison 1982
Munro et al. 1947
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Harrison 1982
Harrison 1982
Munro et al. 1947
Harrison 1982
Harrison 1982
D’Entremont 2010
D’Entremont 2010
D’Entremont 2010
Harrison 1982
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British Columbia, most abundant in winter. . Exclusively marine, breeds on cliffs . Much less gregarious
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Feeds both along rocky shores, hunting in kelp beds, and in deeper oceanic waters .
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.
Anseriformes : Diving Ducks
Diving ducks in the study area include canvasback, ring-necked duck, greater scaup, lesser scaup, harlequin
duck, long-tailed duck, common goldeneye, Barrow’s goldeneye, bufflehead, hooded merganser, common
372 373
merganser, and red-breasted merganser , . Small numbers of long-tailed ducks may occur in the area
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during migration. They move to inland waters, including fjords, in late winter . Here I focus on scoters and
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mergansers. All three scoter species are found over sand-mud and cobble substrates
Surf Scoter – Melanitta perspicillata
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Surf scoter is most numerous scoter in BC , especially common in fjords . On the BC coast they seem to
378
prefer shallow (<6m), open waters of straits, spits and points , but they still outnumber other scoters along the
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steep rock walls of fjords . Surf scoters nest on freshwater lakes but winter along the coast. The species is a
“winter visitant along all the coast; transient in the interior, more common in the Cariboo Parklands and north. A
381
non-breeding population summers on the coast and in the north central interior.” “Surf scoters winter along the
entire length of coastal BC. Fall migrations begins in late August, and birds arrive in the coastal wintering areas
from late September through November. Spring migration begins in late March and peaks in late April to early
May (Campbell et al. 1990a). Non-breeding sub-adults and moulting adults occur in coastal locations during the
382
late summer months. In the winter and spring, very large concentrations of birds occur on the coast.”
Rafts of
surf scoters and white-winged scoters at the north end of Kitimat Arm have occurred between May and July.
383
Large flocks of surf scoters occur in winter (pers. observation) . “During the spring, large concentrations of surf
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scoters will congregate at herring spawning sites within the [Kitimat Fjord System].”
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Propels itself underwater using both wings and feet . “Forages by diving to harvest stationary invertebrates
that dwell on the bottom. Smaller food items are usually swallowed underwater, while large ones are brought to
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the surface first. Often seen diving directly in the surf.”
“In winter, diet consists primarily of…mussels and
clams, with a smaller proportion of crustaceans. During the breeding season it takes freshwater clams, oysters,
387
aquatic worms, insects, leeches and spiders.”
Diet consists mainly of mussels.
Population appears to be declining rapidly
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.
White-winged scoter – Melanitta fusca (Subspecies occurring in BC: deglandi)
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Second-most abundant scoter in BC. , particularly common over gravel beds “Abundant transient across the
interior. Winters in large numbers along the coast, and a number of non-breeding birds remain there all
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summer.” Generally flies very low over the water . Dives occasionally reach up to 60 feet .
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D’Entremont 2010
Trumpeter swans, Canadian geese and Brandt’s also occur in the area during migration.
D’Entremont 2010
Vermeer & Bourne YEAR.
Vermeer & Bourne YEAR.
Vermeer & Bourne YEAR.
D’Entremont 2010
Vermeer & Bourne YEAR.
D’Entremont 2010
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D’Entremont 2010
D’Entremont 2010
D’Entremont 2010
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
D’Entremont 2010
Vermeer & Bourne YEAR.
Vermeer & Bourne YEAR.
Munro et al. 1947
Leslie, S. 2008.
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“Forages by diving to capture bottom-dwelling invertebrate prey.”
Opportunistic feeder, forages in various
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intertidal and subtidal zone substrates . White-winged scoters are chiefly bottom feeding, meaning deep fjordic
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channels aren’t ideal for them . At least 20 bivalve and 20 snail species were encountered as prey .
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Barnacles were the most important crustacean food . “Diet in winter consists largely of bottom-dwelling
invertebrates such as mussels, clams and snails. Sand lance and other small fish are also taken. On its
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breeding grounds, its diet largely consists of awuatic insects and crustaceans .
Black (American) scoter – Oidemia nigra
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Black scoters are comparatively rare . “Winter visitant to coast waters; not recorded from the Interior.” Diet
consists mainly of mussels.
Red-breasted Merganser
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Does not use wings when diving . “Forages by making relatively shallow dives to pursue fish underwater,
which it snaps p with its ‘sawtooth’ bill. Will often hunt cooperatively in a flock, forming a line prior to diving, and
occasionally ‘beating the water with the wings to cause fish to school into a shallower depth. While swimming it
403
will dip its specially adapted eyes just below the surface to locate prey.”
“In winter diet consists almost entirely
of small fish such as minnows, herring, small sculpins, silversides and killifish. Also known to consume small
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invertebrates such as shrimp.” Quite wary of humans .
Anseriformes: Dabbling Ducks
Species include American green-winged teal, American wigeon, Gadwall, mallard, northern pintail, and northern
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shoveler . From his d’Etremont’s (2010) surveys, in the study area, Barrow’s goldeneye was more common
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than common goldeneye . I do not focus in on these species here.
Falconiformes
The falconiformes found over the channels of the Kitimat Fjord System include the bald eagle, osprey, Peale’s
408
peregrine falcon (red-listed in BC and of Special Concern on SARA) and sharp-shinned hawk . Details not
given here.
Charadriiformes : Charadrii
These are less commonly, if ever, seen during transects. I will fill in their natural histories in the months to come:
Black Oystercatcher – Haematopus bachmanii
409
“A resident on, or summer visitant to, the rocky outsid coast and inlets.” “Forages largely in the rocky intertidal and surf zone. Often “jumps” out of the way of crashing waves. Once it locates a mussel or other bivalve
shellfish, it pecks a small hole in the shell then uses its specialized bill to cut the adductor muscle that holds the
shell halves together. Also probes for clams in the mud and sand. Will occasionally hunt for small crabs on
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395
396
397
398
399
400
401
402
403
404
405
406
407
408
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Leslie, S. 2008.
Vermeer & Bourne YEAR.
Vermeer & Bourne YEAR.
Vermeer & Bourne YEAR.
Vermeer & Bourne YEAR.
Leslie, S. 2008.
Vermeer & Bourne YEAR.
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40
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sandy beaches. Walks efficiently with fairly long strides” . “Diet includes sea, bay and horse mussels, limpets,
411
sea urchins, marine worms, crabs, barnacles and clams. Also takes herring eggs when available.”
Semipalmated plover – Charadrius hiaticula
“Scarce transient in the interior, more common on te mainland coast and on Vancouver Island, and a summer
visitant to the open sand and shingle beaches of the Queen Charlotte Islands and extreme northern part of the
412
interior.”
Black-bellied plover – Squatarola squatarola
“A fairly common transient on the coast where it winters more or less regularly on southern Vancouver Island,
and on the beaches adjacent to the mouth of the Fraser River. In the interior it has been recorded on the autumn
413
migration only.”
Surfbird – Aphriza virgate
414
“A transient along the outer coast, and a winter visitant to both coasts of Vancouver Island.”
Turnstone – Arenaria interpres
415
“A scarce transient along the coast.”
Black turnstone – Arenaria melanocephala
416
“Abundant transient and winter visitant on the coast; casual on migration in the central and northern interior.”
Spotted sandpiper – Actitis macularia
417
“Common summer visitant throughout the Province; winters occasionally on the southern coast.”
Solitary sandpiper – Tringa solitaria
“Transient over most of the Province, more common in the interior than on the coast. Present in summer in the
418
northern part of the Province, and in the Peace River Parklands.”
Wandering Tattler – Heteroscelus incanus
“Transient, chiefly observed along the outer coast and the islands in Queen Charlotte Sound; nests near the
419
British Columbia-Yukion boundary.”
Greater Yellow-legs – Totanus melanoleucus
“Abudnant transient throughout most of the Province, scarce in the Boreal Forest; summer visitant to lake edge
meadows, open aspen woods, muskeg and marshes in the Cariboo Parklands and Peace River Parklands biotic
420
areas.”
Lesser Yellow-legs – Totanus flavipes
“Abundant autumn and scarce spring transient. Rare on the coast. Summer visitant to Boreal Forest and Peace
421
River Parklands biotic areas.”
Rock sandpiper - - Erolia ptilocnemis
422
“Abundant winter visitant to the outer coast.”
Sharp-tailed sandpiper – Erolia acuminate
410
411
412
413
414
415
416
417
418
419
420
421
422
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41
“Transient along the coast-line; reported plentiful during the 1941 autumn migration at Masset.”
423
Pectoral sandpiper – Erolia melanotos
424
“Common transient throughout the Province.”
Least sandpiper – Erolia minutilla
425
“A common transient both spring and autumn, relatively scarce in the interior during the spring migration.”
Dunlin – Calidris alpina
“Abundant transient along the coast. Winter visitant, in large numbers, to the Coast Littoral particularly at the
426
mouth of the Fraser River. Scarce in the interior.”
Dowitcher – Limnodromus griseus
427
“Common transient on the coast and in the interior, but scarce in the interior in spring.”
Semipalmated sandpiper – Calidris pusilla
428
“Common autumn transient in the interior, but scarce in spring; rare on the coast.”
Western sandpiper – Ereunetes mauri
“Common transient along the coast; rare in the interior where it has been recorded in the autumn migration
429
only.”
Sanderling – Crocethia alba
“Common transient along the coast, where a few winter on the Fraser River tide flats and on southern
430
Vancouver Island.”
Charadriiformes : Scolopaci: Phalaropodidae
431
All phalaropes are strongly migratory . “The two Arctic species [Red and Red-necked] spend much of their
time at sea and, as in most pelagic species, have developed salt gland to dispense with fresh water
432
indefinitely.” ““Their dense plumage provides a platform of trapped air on which they float, high and cork-like,
433
bobbing their heads as they swim jerkily about.” “Flight weak and nervous.” Sexual role is reversed: females in
434
all species are larger and more brightly colored than males who incubate and tend the young . In winter,
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436
plumage of both sexes similar . “In autumn and winter care is needed to separate the two Arctic species.”
437
“Occasionally spin on water. Tame and confiding, particularly on breeding grounds.”
“Phalaropes are known
for concentrating at surface convergences (Murphy 1936, Lamb 1964, Martin and Myres 1969, Ashmole
438
1971)” .
Red-necked (Northern) phalarope – Lobipes lobatus
439
“Abundant transient throughout the Province. One nesting record for the extreme northwest.” Pelagic when
not breeding, forms flocks at sea, readily alights on water. Red-necked phalaropes nest in lakes and bogs in the
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425
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427
428
429
430
431
432
433
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438
439
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42
extreme north of BC. In the winter they are mainly pelagic. “More birds migrate offshore rather than near shore
and along the inner coast, and fewer still migrate through the interior of British Columbia (Campbell et al.
440
1990b).”
441
They “congregate at tide llines and at the edges of kelp beds to forage on invertebrates.”
Occasionally
442
443
submerges when feeding . Explosive “chip-chip” call in flight . “Likely to be encountered in oceanic habitat
anywhere throughout lower latitudes of southern hemisphere during austral summer with large concentrations in
444
favoured areas” .
Red Phalarope – Phalaropus fucilarius
Rare and rarely seen in the study area. “Transient along the coast, sometimes abundant, occasionally recorded
445
446
from the interior.”
Nests further north and migrates further south . Unlike spring migration, large numbers
447
linger off both coasts of North America until early Dec . Red phalaropes feed on euphausiids, fish eggs,
larvae, and calanoid copepods.
Wilson phalarope – Staganopus tricolor
448
Not expected in the study area. The Wilsons nests around freshwater sloughs and ponds of the central plains .
449
“Regular summer visitant to marshy meadows and sloughs in many parts of the interior, casual on the coast.”
Charadriiformes : Lari : Stercorariidae
Pomarine Jaeger – Stercorarius pomarinus
“A scarce transient in the Coast Littoral Biotic Area, sometimes plentiful in pelagic waters. There is one record
450
451
from the interior of the Province.” Pursues birds as big as the glaucous gull.
Parasitic Jaeger – Stercorarius parasiticus
452
Regular autumn transient along the coast. Usually scarce in spring. . Rarely visits land outside of the breeding
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454
season . A single adult parasitic jaeger was observed flying south over Douglas Channel in 1975 . “Flights
usually purposeful, dashing and rather falcon-like, with jerky wingbeats interspersed with low glides – in any
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wind conditions” . Swims like a gull .
457
458
A kleptoparasite who robs terns and kittiwakes of their catch . An “aggressive, opportunistic feeder.”
“Wideranging diet includes fish and marine invertebrates pirated from other seabirds. Feeds on the eggs and young of
ground-nesting birds such as eiders, shorebirds, ptarmigan and terns. Also eats lemmings and other small
459
mammals. Scavenged detritus and carcasses on beachs and will eat berries.”
Long-tailed Jaeger – Stercorarius longicaudus
460
Scarce transient along the coast and through the interior.
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449
450
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452
453
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Harrison 1982
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Harrison 1982
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Leslie, S. 2008.
D’Entremont 2010
Harrison 1982
Leslie, S. 2008.
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Munro et al. 1947
43
Charadriiformes : Lari : Laridae
Glaucous-winged gull – Larus glaucescens
“An abundant resident along all of the coast. In autumn and winter during and after the salmon spawnin run,
461
many ascent the river for considerable distances but all return to the sea to spend the night.”
Typically the
462
glaucous winged gull is the most abundant gull during Kitimat Estuary Christmas Bird Counts .
“Nests on many rocky islets and islands in the ivsinity of Vicortira….Present in summer, and presumably
nesting, n many rocks and small islands along both coasts of Bancouver Island, both coasts of the Queen
463
Charlotte Islands, Masset Inlet, and the Mainland Coast.”
Glaucous-winged gulls nest at Coste Island Rock
464
and elsewhere near Kitimat Arm .
465
Mew gull – Larus canus, also known as the Common gull or Short-billed gull .
“An abundant winter visitant to the Coast Littoral Biotic Area; regular transient throughout the interior; nests on
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ilsands in Atlin Lake and, less commonly, on Coast lakes and rivers south to Harrison River” .
Western gull – Larus occidentalis
467
An exclusively west coast species . “Regular winter visitant in small numbers to the waters adjoining the Gulf
468
469
Islands Biotic Area.” Largely non-migratory
470
“An opportunist that feeds in a wide variety of ways.” Bill-dipping, shallow lunges, shallow plunges, etc.
“Swallows small prey whole. Drops large shellfish from considerable heights onto the rocks below to break them
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open. Known to take milk directly from lactating seals.”
Herring gull – Larus argentatus
“Summer visitant to the interior and present on the southern lakes during every month in the year; winter visitant
472
473
to the coast” . “A consummate scavenger.”
“Omnivorous and will eat just about anything it finds...frequently
474
scavenges.”
Thayer gull – Larus thayeri
475
“Abundant winter visitant to the Georgia Strait where at times in greatly outnumbers herring gulls” .
California gull – Larus californicus
476
“Transient, in small numbers, on the southern coast and in the interior” .
Bonaparte gull – Larus philadelphia
“Abundant transient throughout the Province, nests locally in the central and northern interior; winters
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occasionally in Georgia Strait” .
“One of the most diverse foraging repertoires of any gulls. Flies close to the water and “dips” to grab food from
the surface, or does very shallow plunge dives into the water to capture small fish and other prey. Also picks
food from the water while swimming on the surface, as well as seizing prey while wading. Forages on land,
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462
463
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465
466
467
468
469
470
471
472
473
474
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476
477
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Leslie, S. 2008.
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479
running very quickly in pursuit of tiny invertebrates on the beach.”
Able to hover and soar . Often swims in
480
little circles to pick insects off water . “Opportunistic feeder, eating whatever suitably sized items are available.
481
Small fish, fish eggs, snails, marine worms, crustaceans and other marine prey are taken.”
Glaucous gull – Larus hyperboreus
“A regular winter visitant on the coast, recorded from the Queen Charlotte Islands south to Victoria. Scarce in
482
the interior.”
Black-legged Kittiwake – Rissa tridactyla
“Regular transient off the west coast of Vancouver Island and in Queen Charlotte Sound. Occasionally winters in
483
484
Coast Littoral waters” . Spends much of its life out of sight of land . Able to drink saltwater (only the
485
kittiwakes among the gulls can do this) . “While on the surface it must tread water with its feet to stay
486
afloat.”
“Forages by making low plunge dives from 3 to 20 ft above the surface and penetrating up to 3 feet underwater
to capture prey. Often hovers close to the water momentarily before grabbing its prey. Also fishes by seizing
487
prey while on the surface or by dipping its bill just underwater.”
“Diet consists primarily of schooling surface
fish such as sand lance, herring and capelin, as well as squid, krill and other small invertebrates. Will also take
488
offal from fishing boats.”
Charadriiformes : Lari : Sternidae
Common tern – Sterna hirundo
489
“Transient in the Georgia Strait and in the interior” . “Forages primarily by plunge diving. Will hover and hold
its position over potential prey until it is within striking distance, then divs into the water from a height of up to 20
490
feet to capture the fish near the surface. Usually penetrates the water no deeper than a foot or two.”
“Diet it
made up primarily of small fish up to about 6 inches long. In coastal areas it includes such species as sand
lance, capelin, herring, shad, pollock, Atlantic mackerel and hake. Also takes a variety of shrimps, crabs and
491
other small crustaceans.”
Arctic tern – Sterna paradisaea
“Transient on the coast and in the interior. Nests on islands in lakes in the extreme northern part of the
492
Province” . “One of the migratory champions of the bird world, the Arctic tern sees more hours of daylight than
any other animal. Its global peregrinations take it from the long days of northern summers in the Arctic where it
breeds to the equally long days of southern summers around Antarctica. With an annual roundt rip of some
25,000 miles and a life span of over 30 years, this little species may migrate 750,000 miles in a lifetime, not
493
including day-to-day foraging flights.”
“Foraging habits similar to common tern.”
494
Caspian & Black terns
495
Caspian (though very rare) and black terns have been recorded near Kitimat Arm .
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479
480
481
482
483
484
485
486
487
488
489
490
491
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493
494
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
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Leslie, S. 2008.
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Leslie, S. 2008.
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Leslie, S. 2008.
45
Charadriiformes : Pan-Alcidae : Alcidae
496
Ten alcid species can occur within a year in the Kitimat Fjord System . The alcids are skillful divers and
497
498
swimmers , using wings to fly under water . Larger forms feed on fish while smaller forms like auklets tend to
499
500
feed on plankton . Some breed in huge colonies .
Common murre – Uria aalge
501
The largest and heaviest of the auks . One of the most abundant marine birds in the seas (up to 9 million
502
503
pairs)
and one of the most studied seabirds in the world . Resident in large numbers in the waters of the
504
Coast Littoral Biotic Area . “Groups of common murres may occur in the outer parts of the Kitimat Fjord
505
System in fall and winter.”
“The common murre often forages far from shore, but will enter inlets and channels where up-welling or mixing
506
507
508
improves foraging opportunities .” Dives up to 60m but the deepest recorded dive is 560 feet . “It is
thought that common murres ascend through large schools of fish from beneath. Feeds both in flocks and
509
510
individually.” Diet consists primarily fish, but also shrimp and other invertebrates . The common murre is
511
red-listed in BC. Common murres are frequently taken as bycatch on the Atlantic coast .
Pigeon gullemot – Cepphus columba
512
“Abundant resident in the Coast Littoral Biotic Area, nesting on rocky islands.” “Commonly seen close to shore
513
in kelp beds, near wharves, in coves.” “Loosely gregarious but nests singly or in small groups, not large
514
515
colonies.” Pigeon guillemot breed at Coste Island in Kitimat Arm .
Marbled Murrelet – Brachyramphus marmoratus
“Resident in Coast Littoral waters along all of the coastline, and on some of the larger lakes, both on the
516
mainland west of the coast mountains and on Vancouver Island” . Marbled murrelets typically nest in trees at
517
elevations above 100m. Nests can be 30 to 80km from the ocean .
Marbled murrelets are Schedule 1 of SARA and on the red list of BC
518
.
Ancient murrelet – Synthliboramphus antiquus
519
520
Nests in dugout burrows , which means they need a sufficient depth of soil for nesting habitat . They are also
521
522
known to burrow in rock crevices in some areas . They return to colonies in April and usually feed out of
523
sight of land . Soon after breeding, ancient murrelets move southward to southern BC and US coasts. By
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498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
D’Entremont 2010
D’Entremont 2010
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Munro et al. 1947
D’Entremont 2010
Campbell et al. 190b
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Piatt et al. 1984.
Munro et al. 1947
Harrison 1982
Harrison 1982
D’Entremont 2010
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D’Entremont 2010
D’Entremont 2010
Gaston 1992.
Gaston 1992.
Gaston 1992.
Gaston 1992.
Gaston 1992.
46
524 525
September, few remain in northern waters
. “Some mystery surrounds the whereabouts of Ancient
526
murrelets during the late summer and early fall.”
Family groups may occur on the outer edge of the Kitimat
527
Fjord System in June .
“Nests on the north and west coasts of Graham Island, and on Lagara Island. Taken in winter as far south as
528
Race Rocks at the southern end of Vancouver Island. There is one interior record” . Have been found feeding
529
on young on herring larvae .
Ancient murrelet is on Schedule 1 of SARA
530
.
Cassin auklet – Ptychoramphus aleuticus
531
532
A plump alcid . One of the most widespread alcids . “Summer visitant to the west coast of Vancouver Island,
533
the Queen Charlotte Islands and Queen Charlotte Sound. Apparently scarce in winter.” Rises swiftly from
534
535
surface, skipping across waves on short, rounded wings with low, direct flight . Nocturnal at colonies .
Rhinoceros Auklet – Cerorhinca monocerata
“Resident and widely distributed along the west coast of Vancouver Island, the Queen Charlotte Islands, and
536
Queen Charlotte Sound. Winter visitant, usually scarce, in Georgia Strait” . “Usually feeds far out at sea
throughout year and, in winter, returns to roost in rafts of many thousands in sheltered bays. In flight almost as
large as Horned Puffin, but wings more pointed appearing generally dark with light belly. Flight strong and direct.
Sits rather low in water, appearing squat and chunky, with head tucked well down revealing little apparent
537
neck” .
Tufted puffin – Lunda cirrhata
538
“Tufted puffins are unlikely to occur within the Kitimat Fjord System.”
“Summer visitant along the [BC] coast,
539
least plentiful in Georgia Strait” , though it is “one of the most abundant and conspicuous seabirds of
540
541
542
Alaska” . Requires a long run-off to become airborne . Strong and direct flight 20-30m high . More pelagic
543
than congeners .
544
In flight it uses its feet to help steer . This puffin is a dive-pursuit forager, using wings for underwater
545
546
547
propulsion . Most dives probably less than 200 feet deep . Diet is a combination of fish and invertebrates .
When obtaining food for their young, they take mostly fish such as anchovy, sand lance, young pollock and
548
capelin .
Horned Puffin - Fratercula corniculata
549
Small colony recently discovered in Queen Charlotte Islands, BC. Adults also seen around Triangle Island .
Fledging and dispersal occurs in September or October to spend winter far out at sea. Rarer further south off
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527
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530
531
532
533
534
535
536
537
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539
540
541
542
543
544
545
546
547
548
549
Campbell et al. 1990b
D’Entremont 2010
Gaston 1992.
D’Entremont 2010
Munro et al. 1947
Gaston 1992.
D’Entremont 2010
Harrison 1982
Harrison 1982
Munro et al. 1947
Harrison 1982
Harrison 1982
Munro et al. 1947
Harrison 1982
D’Entremont 2010
Munro et al. 1947
Harrison 1982
Harrison 1982
Harrison 1982
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
Harrison 1982
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550
Washington and Oregon . The horned puffin captures food by diving
552
553
opened wings Most dives are probably less than 30m .
551
. propeling itself underwater using half-
Important Bird Areas (IBAs)
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555
550
551
552
553
554
555
Harrison 1982
Leslie, S. 2008.
Leslie, S. 2008.
Leslie, S. 2008.
D’Entremont 2010
D’Entremont 2010
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IBA BC106 – Moore and Byers Islands and Banks
“The Moore and Byers Islands and Banks IBA (IBA BC106) lie along the east side of Hecate Strait, between the
north end of Vancouver Island and Prince Rupert. The site is approximately 100 km northwest of Bella Bella, 10
to 18 km off the west coast of Aristazabal Island, and includes all the islands, islets and reefs in this area (Figure
3-1). The northern and southern islands are separated by Wright Passage. The IBA includes the shallow marine
water within a 10 km radius of the island chain. Many of the smaller islands are dominated by Sitka spruce,
556
whereas the larger islands have grassy and herbaceous cover.”
“The majority of the marine-bird breeding habitat is located on 7 of the 12 islands in the IBA. Surveys conducted
by Rodway and Lemon (1991) reported that 30,040 pairs of Forked-tailed Storm-petrels and 20,505 pairs of
Leach’s Storm-petrels nest within the IBA. Their survey also recorded 79 breeding pairs of Black Oystercatchers
557
distributed over all 12 islands.”
“Three alcid species breed here in substantial numbers. These include the Rhinoceros Auklet (91,640 pairs),
Cassin’s Auklet (22,730 pairs) and Pigeon Guillemot (302 pairs); (Rodway and Lemon 1991). In addition, 889
558
pairs of Glaucous-winged Gulls bred here in 1988 (Rodway and Lemon 1991).”
Moore, McKenney, Whitmore Islands Ecological Reserve
This island reserve is located just southwest of Parker Passage between Aristazabal and Rennison Islands in
Caamano Sound. It and another reserve, the Byers/Conroy/Harvey/Sinnett Islands ER, encompass enormous
nesting colonies of seabirds including rhinoceros (at least 90,000 pairs, 7% of the world population) and
Cassin’s auklets, storm-petrels and guillemots. These birds feed within the KFS during the summer. The primary
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role of these ecological reserves is to protect nesting habitat for these seabirds .
“The Moore and Byers Islands and Banks Island Ecological Reserve support a breeding population of Ancient
Murrelets on South Moore and the smaller islands (BC MoE 2003b, Internet site); however, the number of
breeding pairs is unknown. The Ecological Reserve may support breeding Marbled Murrelets, but this has not
been confirmed. This Ecological Reserve is closed to the public. Research or educational activities may be
560
conducted, but only with authorization from the province of British Columbia.”
Dewdney and Glide Islands Ecological Reserve
The Dewdney and Glide Islands Ecological Reserve, on the northwest corner of Caamano Sound, has only been
surveyed once by naturalists, in 1987. This document shares notes from that field trip, including an encounter
with coastal wolves, adventures in sphagnum bogs, minnow traps, and no evidence of human presence. “The
561
density of blackflies was beyond description and quantification.”
“This Ecological Reserve includes an extensive bog and fen ecosystem found on outer islands of the north
coast. The reserve contains nesting habitat for several birds with restricted breeding ranges in British Columbia,
such as Sandhill Crane and Cassin’s Auklet (BC MoE 2003f, Internet site). Other coastal birds that use the
reserve include Bald Eagle and Great Blue Heron. This Ecological Reserve is closed to the public. Research or
562
educational activities may be conducted, but only with authorization from the province of British Columbia.”
556
557
558
559
560
561
562
D’Entremont 2010
D’Entremont 2010
D’Entremont 2010
Mazur & Wilkin 2003.
D’Entremont 2010
Reimchen and Douglas 1987.
D’Entremont 2010
49
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Ballance, L. 2013. Marine mammal taxonomy. Marine Tetrapods. Scripps Institution of Oceanography. Lecture
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Ballance, L. 2013. Seabird taxonomy. Marine Tetrapods Lecture, Week 2.
Barlow J, Calambokidis J, Falcone EA, Baker CS, Burdin AM, et al. (2011) Humpback whale abundance in the
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