The Primates
compiled by Dana Visalli
A male Mandrill
Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics
represent adaptations to life in this challenging three-dimensional environment. Most primate species
remain at least partly arboreal. There are a surprisingly large number of primates, or ‘monkeys and their
kin.’ The total number is variable, but settles in the range of about 300 species. The word ‘primate’
comes from a Latin root meaning ‘first rank’ or ‘numeral uno,’ a reflection of ever-present anthropocentrism (human self-centeredness) of our species, which tends to judge nearby Homo sapiens (which means
‘wise man’) as the pinnacle of the infinitely long evolutionary journey, while those Homo sapiens at a distance are often considered to be ‘the other’ and ‘the enemy’ and therefore not wise at all.
Primates range in size from a tiny lemur in Madagascar called Madame Berthe’s Mouse Lemur, which
weighs one ounce, to the lowland gorillas in Africa, which weigh in at well over 400 pounds. Genetic
studies indicate that the primate line originated about 85 million years ago, in the mid-Cretaceous Period. New primate species are still being discovered. More than 25 species were taxonomically described
in the decade of the 2000s and eleven have been described since 2010.
Primates are characterized by large brains relative to other mammals, as well as an increased reliance on
stereoscopic vision at the expense of smell, the dominant sensory system in most mammals. These
features are more developed in monkeys and apes and noticeably less so in lorises and lemurs. Most
primates have opposable thumbs and some have prehensile tails. Many species are sexually dimorphic,
meaning males and females are markedly different in size; in primates males are typically larger than
females (in contrast to raptors, in which females are typically larger). Depending on the species, adults
may live in solitude, in mated pairs, or in groups of up to hundreds of members.
Many primate species are now in danger of becoming extinct. The primary cause is deforestation, driven
ultimately by human population growth and over-consumption of the Earth’s resources. Additional
pressure is placed on primate populations by humans hunting them to sell for food and pets. Monkeys
and apes are popular sources of ‘bush meat’ in Africa.
Dana Visalli/[email protected]/www.methownaturalist.com
Today, non-human primates are limited in their natural habitats primarily to the tropical and subtropical
regions of the New and Old Worlds. They have never lived in Australia and most of the islands in the
Pacific Ocean. However, the earliest primates also lived in North America and Europe beginning around
55-50 million years ago.
In primate evolution, there was a progressive reduction in nose size and in the olfactory areas of the
brain. Lemurs are an exception; they are very much like the early primates 50 million years ago. As the
primate nose progressively shrank in size over millions of years, there was a corresponding increase in
visual capabilities. As much as 50% of the cerebral cortex in some species of monkeys is involved in visual processing. Many primates have color vision comparable to our own. All have binocular vision with
fields of view that significantly overlap, resulting in true three dimensional depth perception or stereoscopic vision. At the same time, the field of view for peripheral vision was reduced.
Compared to most other animals, primate brains are large relative to their body size. Those areas of the
brain that are involved with controlling manual dexterity, eye-hand coordination, and stereoscopic vision have particularly expanded. These traits were probably selected by nature mostly due to their usefulness in traveling in trees. Almost all primates are diurnal, which is to say, they are active during the day
and sleep at night.
Generally, primates are highly social animals. Most of their waking hours are spent socializing with each
other. This is made easier by complex vocalizations and visual displays. In addition, they regularly
groom each other, thereby keeping clean and satisfying psychological needs at the same time. Grooming
is a very pleasurable activity for primates, including humans.
Primates have been very successful animals due largely to the fact that they are intelligent (have relatively flexible behavior; they not completely dominated by genetic programming) and are opportunistic in
obtaining food. Many species are omnivorous, though vegetable foods usually make up the bulk of calories consumed by most primate species because they are easier to obtain. By comparison, animals such as
koalas and giant pandas are generally less successful because they are extremely limited in the kinds of
foods that they can or will eat. Koalas subsist on the leaves of a few species of eucalyptus, and giant pandas primarily eat the shoots of a small number of bamboo species. If these food sources are not available,
koalas and giant pandas die. Not surprisingly, their highly limited range of foods restricts where they
can live. This is not the case with most primate species.
Families of Primates
1. Dwarf & Mouse Lemurs- Family Cheirogaleidae: 34 species. This
family lives exclusively on the island of Madagascar; they are the
smallest of the primates. Dwarf and mouse lemurs are nocturnal and
arboreal. They are excellent climbers and can also jump far, using their
long tails for balance. When on the ground (a rare occurrence), they
move by hopping on their hind legs. They spend the day in tree
hollows or leaf nests. They are typically solitary, but sometimes live
together in pairs. They are omnivores, eating fruits, flowers, leaves and
Madame Berthe’s Mouse Lemur
sometimes nectar, as well as insects, spiders, and small vertebrates.
Madame Berthe's mouse lemur (Microcebus berthae) is the smallest of the mouse lemurs and the smallest
primate in the world; the average body length is 9.2 cm (3.6 in) and seasonal weight is around 30 g
(1.1 oz). It was discovered in 1992
2. Lemurs- Family Lemuridae: 21 species. This is one of five families commonly known as lemurs, all
native to Madagascar. These animals were once thought to be the evolutionary predecessors of monkeys
2
and apes, but this is no longer considered correct. Lemurids are mediumsized arboreal primates, ranging from 32 to 56 cm (12-22 in) in length,
excluding the tail, and weighing from 0.7 to 5 kg (1.5-11 lbs). They have
long, bushy tails and soft, woolly fur of varying coloration. Most species are
highly agile, and regularly leap several metres between trees.
3. Sportive Lemurs- Family Lepilemuridae: 26 species. Medium sized
primates living only in Madagascar. They are strictly nocturnal,
predominantly arboreal, and eat primarily leaves. They got their name
from their leaping abilities.
4. Woolly Lemurs & Sifakas- Family Indriidae: 19 species. All species are
arboreal, though they do come to the ground occasionally. When on the
ground, they stand upright and move with short hops forward, with their
arms held high. In the trees, though, they can make extraordinary leaps
and are extremely agile, able to change direction from tree to tree. Like
most leaf eaters they adjust for the low nutrient content of their food by
long rests. Often they can be seen lying stretched on trees sunning
themselves. Indrids live together in family federations from 2 to 15 animals,
communicating with roars and also with facial expressions. Indrids are
herbivores, eating mostly leaves, fruits and flowers.
5. Aye-Aye- Family Daubentoniidae: 1 species. The aye-aye (Daubentonia
madagascariensis) is a lemur, a native to Madagascar that combines rodentlike teeth and a special thin middle finger to fill the same ecological niche
as a woodpecker. It is the world's largest nocturnal primate, and is
characterized by its unusual method of finding food; it taps on trees to find
grubs, then gnaws holes in the wood using its forward slanting incisors to
create a small hole in which it inserts its narrow middle finger to pull the
grubs out. It is currently classified as Endangered, and a second species,
Daubentonia robusta, appears to have become extinct at some point within
the last 1000 years. A full-grown aye-aye is typically about three feet long
with a tail as long as its body
Ring-tailed Lemur
Sportive Lemur
Silky Sifaka (critically endangered)
Aye-Aye
6. Lorises, Pottos, Bushbabies & Galagos-Family Lorisidae: 28 species.
Lorisids live in tropical, central Africa as well as in south and southeast
Asia. The are slim, nocturnal, arboreal primates that are either solitary or
live in small family groups. The main diet of most lorisids consists of
insects, but they also consume bird eggs and small vertebrates as well as
fruits and sap.
7. Galagos- Galagidae: 19 species. Also known as Bushbabies. Small,
nocturnal primates of Africa only. According to some accounts, the name
"bush baby" comes from either the animal's cries or its appearance. Galagos
have large eyes that give them good night vision, strong hind limbs, acute
hearing, and long tails that help them balance. Their ears are batlike and
allow them to track insects in the dark. They catch insects on the ground or
snatch them out of the air. They are fast, agile creatures. As they bound
through the thick bushes, they fold their delicate ears back to protect them.
They have nails on most of their digits, except for the second toe of the
3
Red Slender Loris
Garnett’s Galago
hindfoot, which bears a 'toilet' claw for grooming. Their diet is a mixture of
insects and other small animals, fruit, and tree gums. young galagos are
born with half-closed eyes and are initially unable to move about
independently. After a few days, the mother carries the infant in her mouth,
and places it on branches while feeding. Females may have singles, twins, or
triplets and may become very aggressive. Each new born weighs less than
half an ounce. The young are fed by the mother for six weeks and can feed
themselves at two months. Females maintain their territory, but share them
Brown Greater Galago
with their offspring. Males leave their mothers' territories after puberty, but females remain, forming
social groups consisting of closely related females and their young. Adult males maintain separate
territories, which overlap with those of the female social groups; generally, one adult male mates with all
the females in an area. Males who have not established such territories sometimes form small bachelor
groups. At the end of the night, group members use a special rallying call and gather to sleep in a nest
made of leaves, a group of branches, or a hole in a tree.
8. Tarsiers- Tarsiidae: ll species. This family was once more widespread, but
all the species living today are found in the islands of Southeast Asia.
Tarsiers are small animals with enormous eyes; each eyeball is
approximately 16 mm in diameter and is as large as its entire brain. The
unique cranial anatomy of the tarsier results from the need to balance their
large eyes and heavy head so they are able to wait silently for nutritious
prey. Tarsiers have an incredibly strong auditory sense because their
Tarsier
auditory cortex is very distinct. Tarsiers also have very long hind limbs, due
mostly to the extremely elongated tarsus bones of the feet, from which the animals get their name.
Tarsiers are the only extant entirely carnivorous primates: they are primarily insectivorous, and catch
insects by jumping at them. They are also known to prey on birds, snakes, lizards, and bats. All tarsiers
are considered vulnerable to extinction.
9. Marmosets & Tamarins- Family Callitrichidae: 43 species. A family of
New World monkeys. They are all arboreal, relatively small and eat insects,
fruit, and the sap or gum from trees; occasionally they will take small
vertebrates. The marmosets rely quite heavily on tree exudates. Callitrichids
typically live in small, territorial groups of about five or six animals. Their
social organization is unique among primates and is called a "cooperative
polyandrous group". This communal breeding system involves groups of
Emperor Tamarin
multiple males and females, but only one female is reproductively active.
Females mate with more than one male and everyone shares the responsibility of carrying the offspring.
They are the only primate group that regularly produces twins, which constitute over 80% of births in
species that have been studied. Unlike other male primates, male callitrichids generally provide as much
parental care as females.
10. Capuchins, Squirrel Monkeys & Night Monkeys- Family Cebidae: 26
species. One of 5 New World monkeys, these species are found throughout
tropical and subtropical South and Central America. Cebid monkeys are
arboreal animals that only rarely travel on the ground. They are generally
small monkeys, ranging in size up to that of the Brown Capuchin, with a
body length of 33 to 56 cm (13-22 in), and a weight of 2.5 to 3.9 kilograms
(5-8/5 ;bs). They are somewhat variable in form and coloration, but all have
the wide, flat, noses typical of New World Monkeys. They are different from
marmosets as they have additional molar tooth and a prehensile tail. They
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Tufted Capuchin
are omnivorous, mostly eating fruit and insects, although the proportions of these foods vary greatly
between species.
11. Night or Owl Monkeys, also called Douroucoulis- Family Aotidae:
11 species. The only nocturnal New World monkeys, they are native to
Panama and much of tropical South America. Night monkeys have large
brown eyes; the size improves their nocturnal vision, thus increasing their
ability to be active at night. Their ears are rather difficult to see; this is
why their genus name, Aotus (meaning "earless") was chosen. They are
small, weighing from .5-1.3 kg (1-3 lbs). Night monkeys make a notably
Nancy Ma’s Night Monkey
wide variety of vocal sounds, with up to eight categories of distinct calls
(gruff grunts, resonant grunts, screams, low trills, moans, gulps, sneeze grunts and hoots), and a
frequency range of 190-1,950 Hz. Unusual among the New World monkeys, they are monochromats, that
is, they have no colour vision, presumably because it is of no advantage given their nocturnal habits.
They have a better spatial resolution at low light levels than other primates, which contributes to their
ability to capture insects and move at night. Night monkeys live in family groups consisting of a mated
pair and their immature offspring. Family groups defend territories by vocal calls and scent marking.
The night monkey is socially monogamous, and all night monkeys form pair bonds. Only one infant is
born each year. The male is the primary caregiver, and the mother only carries the infant for the first
week or so of its life. This is believed to have developed because it increases the survival of the infant and
reduces the metabolic costs on the female.
12. Titis, Sakis and Uakaris- Family Pitheciidae: 30 species. One of 5
families of New World monkeys, most species are native to the Amazonia
region of Brazil, with some being found from Colombia in the north to
Bolivia in the south. Pithecids are small to medium-sized monkeys,
ranging from 23 cm in head-body length for the smaller titis, to 44-49 cm
for the uakaris. They are diurnal and arboreal animals, found in tropical
forests from low-lying swamp to mountain slopes. They are
predominantly herbivorous, eating mostly fruit and seeds, although some
White-faced Saki
species will also eat a small number of insects. The uakaris and bearded
sakis are polygamous, living in groups of 8-30 individuals. Each group has multiple males, which
establish a dominance hierarchy amongst themselves. The titis and sakis, by contrast, are monogamous
and live in much smaller family groups.
13. Howler, Spider and Woolly Monkeys- Family Atelidae: 29 species.
Atelids are generally larger monkeys and are found throughout the
forested regions of Central and South America, from Mexico to northern
Argentina. Howler monkeys are the largest members of the group, and
the spider monkeys the smallest. They have long prehensile tails with a
sensitive, almost hairless, tactile pad on the underside of the distal part.
The tail is frequently used as 'fifth limb' while moving through the trees
where they make their homes. They also have nails on their fingers and
Black Howler Monkeys
toes, enabling them to climb. Most species have predominantly dark brown, grey, or black fur, often with
paler markings. These are arboreal and diurnal animals, with most species restricted to dense rain forest,
although some howler monkey species are found in drier forests, or wooded savannah. They mainly eat
fruit and leaves, although the smaller species, in particular, may also eat some small insects. Atelid
monkeys are typically polygamous, and live in social groups with anything up to twenty five adults,
depending on species. Where groups are relatively small, as is common amongst the howler monkeys, a
5
single male monopolises a 'harem' of females, but larger groups will contain several males, with a clear
hierarchy of dominance.
14. Old World Monkeys- Family Cercopithecidae: 138 species. The Old
World monkeys are native to Africa and Asia today, inhabiting a range of
environments from tropical rain forest to savanna, shrubland and
mountainous terrain, and are also known from Europe in the fossil record.
However, a (possibly introduced) free-roaming group of monkeys still
survives in Gibraltar (Europe) to this day. Old World monkeys include
many of the most familiar species of nonhuman primates, such as
baboons and macaques. Old World monkeys are medium to large in size,
Vervet Monkey
and range from arboreal forms, such as the colobus monkeys, to fully terrestrial forms, such as the
baboons. The smallest is the talapoin, with a head and body 34–37 cm in length, and weighing between
0.7 and 1.3 kilograms, while the largest is the male mandrill (the females of the species being significantly
smaller), at around 70 cm in length, and weighing up to 50 kilograms. Old World monkeys are unlike
apes in that most have tails (the family name means "tailed ape"), and
unlike the New World monkeys in that their tails are never prehensile.
Most Old World monkeys are at least partially omnivorous, but all prefer
plant matter, which forms the bulk of their diet. Leaf monkeys are the
most vegetarian, subsisting primarily on leaves, and eating only a small
number of insects, while the other species are highly opportunistic,
primarily eating fruit, but also consuming almost any food items available,
such as flowers, leaves, bulbs and rhizomes, insects, snails, and even
small vertebrates. In most species, daughters remain with their mothers
Mandrill, rear view
for life, so that the basic social group among Old World monkeys is a matrilineal troop. Males leave the
group on reaching adolescence, and find a new troop to join. In many species, only a single adult male
lives with each group, driving off all rivals, but others are more tolerant, establishing hierarchical
relationships between dominant and subordinate males. Group sizes are highly variable, even within
species, depending on the availability of food and other resources.
15. Gibbons or Lesser Apes- Family Hylobatidae: 16 species. Gibbons
occur in tropical and subtropical rainforests from northeast India to
Indonesia and north to southern China, including the islands of Sumatra,
Borneo, and Java. Also called the lesser apes, gibbons differ from great
apes (chimpanzees, gorillas, orangutans, bonobos and humans) in being
smaller, exhibiting low sexual dimorphism, in not making nests, and in
certain anatomical details in which they superficially more closely
Lar Gibbons
resemble monkeys than great apes do. But like all apes, gibbons evolved
to become tailless. Gibbons also display pair-bonding, unlike most of the great apes. Gibbons are masters
of their primary mode of locomotion, brachiation, swinging from branch to branch for distances of up to
15 m (50 ft), at speeds as high as 55 km/h (34 mph). They can also make leaps of up to 8 m (26 ft), and
walk bipedally with their arms raised for balance. They are the fastest and
most agile of all tree-dwelling, non-flying mammals. Some species have
an enlarged throat sac, which inflates and serves as a resonating chamber
when the animals call. This structure is enormous in a few species,
equaling the size of the animal's head. Their voice is much more powerful
than that of any human singer, although they are at best half a man's
height. Gibbons are social animals. They are strongly territorial, and
defend their boundaries with vigorous visual and vocal displays. The
vocal element, which can often be heard for distances of up to 1 km
Agile Gibbon
6
(0.6 mi), consists of a duet between a mated pair, with their young
sometimes joining in. In most species, males, and in some also females,
sing solos to attract mates, as well as advertise their territories. The song
can be used to identify not only which species of gibbon is singing, but
also the area from which it comes. Most species are endangered, primarily
due to degradation or loss of their forest habitats.
16. Great Apes- Family Hominidae: 7 species. The Great Apes include
four extant genera: the chimpanzees (Pan) with 2 species; gorillas (Gorilla)
with 2 species; humans (Homo) with 1 species; and orangutans (Pongo)
with 2 species. The ancestors of the Hominidae family speciated from
those of the Hylobatidae family perhaps 15 million to 20 million years
ago.Molecular evidence suggests that between 8 and 4 million years ago,
first the gorillas, and then the chimpanzees and bonobos (genus Pan) split
off from the line leading to the humans; human DNA is approximately
98.4% identical to that of chimpanzees. A hominin is a member of the tribe
Hominini; modern humans and their extinct relatives, although many
scientists, including paleoanthropologists, continue to use the term
hominid to mean humans and their direct and near-direct bipedal
ancestors.
Orangutans- Pongo: 2 species. Found only on the Islands of Sumatra and
Borneo. A century ago there were about 230,000 orangutans; today there
are about 40,000 Bornean orangutans and 7500 Sumatran; the latter are
considered critically endangered. The orangutans were the first apes to
diverge from an ancestor common to all great apes. They are sexually dimorphic, with females reaching 45 kg (100 lbs) and males 115 kg (260 lbs).
Fruit is the most important component of their diet, however they will also
eat vegetation, honey, insects and bird eggs.
Western Hoolock Gibbon (endangered)
Bonobo
Orangutan (endangered)
Gorilla- 2 species; there are thought to be about 100,000 Lowland Gorillas
and about 800 Mountain Gorillas in existence; obviously the latter are critically endangered. They are found only in central Africa. Gorillas grow to 2
meters (6.5 ft) tall and 180 kg (400 lbs). They are herbivores, eating mostly
leaves. Gorillas are the second great ape to split away from a common ancestor, about 8 million years ago. Gorillas spend most of their time on
ground, though they are adept in trees.
Chimpanzees- Pan: 2 species. Chimps diverged from the human lineage
about 7 million years ago; they differ from humans in genetic makeup by
about 1%. There are thought to be about 200,000 chimps and 50,000 bonobos (which are endangered). Bonobos have only been recognized as a species apart from chimps since 1929. Male bonobos weigh about l00 pounds,
females 70 pounds, both grow to about 3’8” tall. They are found only in
the Democratic Republic of Congo (DRC). Bonobos are bipedal 5% of the
time, usually when carrying food or other objects. They forage mostly in
trees, sometimes on the ground. Chimpanzee males weigh 110 pounds
and females weigh 100 pounds, they are about 4’ tall. Chimpanzees use
rocks as hammers to crack nuts and teach their young the technique.
Chimps are the only other primate species besides Homo sapiens known to
use male allegiance systems to systematically kill males in other groups.
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Male Moutain Gorilla (endangered)
Male Lowland Gorilla
An enduring mystery among the primates is where the New World monkeys came from. The two groups
are markedly different but must have had a common ancestor. The prominent distinction is the nose,
which in New World monkeys is flat and has side-facing nostrils, while Old World monkeys have narrow noses. New World monkeys are the only monkeys with prehensile tails, which means they can use
the tail for grasping. The two groups split about 40 million years ago. How this happened is open to conjecture, as there has been no terrestrial connection between the Old World and New for millions of years.
The Atlantic would have been about one-third less wide 40 million years ago, and it is considered possible that a founder population rafted across the chasm on floating vegetation.
The 16 Primate Families
1. Dwarf & Mouse Lemurs- Cheirogaleidae: 34 species, Madagascar
2. Lemurs- Lemuridae: 21 species, Madagascar
3. Sportive Lemurs- Lepilemuridae: 26 species, Madagascar
4. Woolly Lemurs & Sifakas- Indriidae: 19 species, Madagascar
5. Aye-aye- Daubentoniidae: 1 species, Madagascar
6. Lorises & Pottos- Lorisidae: 28 species, central Africa & south Asia
7. Galagos & Bushbabies- Galagidae: 19 species, widespread in Africa
8. Tarsiers- Tarsiidae: 11 species, Indonesia, Borneo, Philippines
9. Marmosets & Tamarins- Callitrichidae: 43 species, South (mostly) & Central America
10. Capuchins & Squirrel Monkeys- Cebidae: 26 species, Central & South America
11. Night Monkeys- Aotidae: 11 species, Central & South America
12. Titis, Sakis and Uakaris- Pitheciidae:30 species, South America
13. Howler, Spider & Woolly Monkeys- Atelidae: 29 species, Central & South America
14. Old World Monkeys- Cercopithecidae: 138 species, Africa & Asia
15. Gibbons- Hylobatidae: 16 species, Indonesia, northeast India and southern China
16. Great Apes- Hominidae: 7 species, central Africa
Dana Visalli/[email protected]/www.methownaturalist.com
The World’s 25 Most Endangered Primates
Blue-eyed black lemur- Eulemur flavifrons- Madagascar- remaining population: 1500
Northern sportive lemur- Lepilemur septentrionalis- Madagascar- remaining population: 18
Silky sifaka- Propithecus candidus- Madagascar- remaining population: 225
Madame Berthe's mouse lemur- Madagascar- Microcebus berthae- remaining population: 8000
Red ruffed lemur- Varecia rubra- Madagascar- remaining population: unknown
Indri- Indri indri- Madagascar- remaining population: unknown
Rondo dwarf galago- Galagoides rondoensis- Tanzania- remaining population: unknown
Roloway monkey- Cercopithecus roloway- Ghana- remaining population: unknown
Tana River red colobus- Procolobus rufomitratus- Kenya- remaining population: 11200
Bioko red colobus- Piliocolobus pennantii pennantii- Equatorial Guinea- remaining population: 4800
Eastern lowland gorilla- Gorilla beringei graueri- DRC- remaining population:s 100,000
Javan slow loris- Nycticebus javanicus- Java- remaining population: unknown
Pig-tailed langur- Simias concolor- Indonesia- remaining population: 2500
Delacour's langur- Trachypithecus delacouri- Vietnam- remaining population: 225
Golden-headed langur- Trachypithecus poliocephalus poliocephalus- Vietnam- remaining population: 60
Western purple-faced langur- Trachypithecus vetulus nestor- Sri Lanka- remaining population: unknown
Grey-shanked douc- Pygathrix cinerea- Vietnam- remaining population: 600
Tonkin snub-nosed monkey- Rhinopithecus avunculus- Vietnam- remaining population: 250
Eastern black crested gibbon- Nomascus nasutus- China & Vietnam- remaining population: 110
Pygmy tarsier- Tarsius pumilus- Indonesia- remaining population: unknown
Brown spider monkey- Ateles hybridus- Columbia & Venezuela- remaining population: unknown
Brown-headed spider monkey- Ateles fusciceps fusciceps- Ecuador- remaining population: unknown
Kaapori capuchin- Cebus kaapori- Brazil- remaining population: unknown
Rio Mayo titi- Callicebus oenanthe- Peru- remaining population: unknown
Northern brown howler- Alouatta guariba guariba- Brazil- remaining population: 225
With each new publication, species are both
added and removed from the list. In some
cases, removal from the list signifies
improvement for the species. With the
publication of the 2006–2008, four species were
removed from the list because of increased
conservation efforts: the black lion tamarin
(Leontopithecus chrysopygus), golden lion
Red ruffed lemur
Indri
tamarin (Leontopithecus rosalia), mountain gorilla (Gorilla beringei beringei), and Perrier's sifaka (Propithecus
perrieri). In 2008, the black lion tamarin went from Critically Endangered to Endangered and the golden
lion tamarin was similarly promoted in 2003 after three decades of collaborative conservation efforts by
zoos and other institutions. Well-protected species such as these still have very small populations, and due
to deforestation, new habitat is still needed for their long-term survival. The Hainan black crested gibbon
(Nomascus hainanus), which was removed
from the 2008–2010 list, still has fewer than 20
individuals left, but significant efforts to
protect it are now being made. Russell
Mittermeier claimed in 2007 that all 25 species
would be elevated off the list within five to
ten years if conservation organizations had
the necessary resources.
Tonkin Snub-nosed Monkey
Gray-shanked Douc