North American River Otter
Interpretive Guide
Exhibit Talking Points: Our job as interpreters is to link what the visitors are seeing to The Zoo's
conservation education messages. Our goal is to spark curiosity, create emotional connections
and inspire visitors to take action. The best way to achieve this goal is to share thematic
information that connects to The Zoo's messaging. To help you successfully engage with visitors
at the otter exhibit, some thematic talking points are listed below.
Theme: Humans are part of the rich diversity of life and have the power to protect or destroy it.
Talking point: Wetland/watershed conservation
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Possible hooks: Where have you seen animals like this in the wild?
Related information:
o North American river otters live in a variety of aquatic habitats like rivers,
streams, tidewater zones and estuaries.
o N.A. river otters swim thorough water to find prey and escape from predators.
o Runoff from storms can wash pollutants like trash, sediment, nutrients and
chemicals into waterways, which can make animals like otters sick.
o N.A. river otter populations had declined greatly in the past due to over hunting
and pollution. The improvement of water quality in the northeast was a
contributing factor to their population rebound and successful reintroduction.
o It is important to keep our watershed clean and healthy so that the wildlife living
within it stays healthy.
Call to action: Encourage visitors to make environmentally responsible lifestyle choices
to help conserve our watershed. Some examples are listed below.
o Get involved with your community: Support legislation that helps to protect our
watershed; participate in neighborhood trash clean-ups; work with the
community to organize a hazardous waste disposal day.
o Take steps to reduce water pollution in our watershed. Dispose of trash properly
and pick up litter.
o Use pesticides and other hazardous materials sparingly and dispose of them
properly to ensure that they do not end up in waterways.
Theme: Living things live within complex relationships in ecosystems.
Talking point: N.A river otters are predators
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Possible hooks: Why do you think otters need to swim?
Related information:
o N.A. river otters are carnivorous. They mostly eat small fish, but also eat
crustaceans, amphibians, insects, and the occasional small mammal.
o Otters are great swimmers; they have streamlined bodies, webbed feet, a strong
tail, and waterproof fur.
o Otters have long whiskers that are sensitive to the slightest movements in the
water. These whiskers help otters locate fish moving through the water.
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North American River Otter
The Maryland Zoo
North American River Otter
Interpretive Guide
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o In addition to being physically adapted for hunting and swimming in the water,
N.A. river otters are intelligent. One way they exhibit their intelligence is through
problem solving. For example, N.A. river otters sometimes create small
whirlpools by swimming in tight circles to bring up fish from deeper water.
Call to action:
o N.A. river otters are not the only animals that create whirlpools while hunting;
northern shovelers also exhibit this behavior. Encourage visitors to explore the
Marsh Aviary.
o N.A. river otters depend on clean water to hunt successfully, encourage visitors
to make environmentally responsible choices to help conserve our watershed.
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North American River Otter
The Maryland Zoo
North American River Otter
Lontra canadensis
Description:
 Size:
o Length: 18-32 in (46-83 cm)
o Weight: 6-31 lb (3-14 kg)
 Physical Description: North American river otters are a large semiaquatic weasel. They
have short legs, muscular and streamlined bodies, small heads and long, powerful tails.
Their whiskers are long and thick and their feet are clawed and webbed.
 Coloration: Their backs are dark brown to almost black, while their undersides are
lighter brown to tan.
 Sexual dimorphism: Males are larger than females
In the Wild
Habitat and Range:
 Range: Found throughout most of Canada and the United States Historically extirpated
through much of their range, especially in the east, but reintroduction efforts have been
successful.
 Habitat: River otters prefer habitats with access to water and a stable food supply. They
can be found, in fresh, brackish and coastal saltwater environments. Examples include
lakes, rivers, marshes, swamps, and estuaries. River otters have a wide tolerance for
temperature, being found in both warm and cold climates, but have a low tolerance for
polluted waters.
o In Maryland, river otters live in tidewater areas across the state.
Diet:
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Carnivorous: Mostly eats small, slow moving fish
o Also eats frogs, crayfish, crustaceans, rodents, rabbits and insects
o Rarely eats aquatic plants and other plant matter
Adaptations:
 Aquatic adaptations:
o Long, thick whiskers help them find prey
o Webbed feet help them swim
o Thick, oily fur keeps them dry and insulates them from the water
o Tails are muscular and aid in propulsion in the water
o Streamlined bodies provide for aquatic agility
 Prevent water from entering nasal cavity or ear canals by closing nostrils and ears when
swimming
 Land adaptations:
o Sharp claws allow them to dig and climb.
o Long flexible body allows for quick and agile movements
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North American River Otter
The Maryland Zoo
North American River Otter
Lontra canadensis
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o Use their long abdomen to slide across slippery surfaces like snow, ice, grass or
mud, to move quickly from place to place on land
Intelligence and problem solving ability enables them to hunt and capture prey in novel
ways. For example, they sometimes hunt by swimming in very tight circles, creating a
whirlpool-like motion that brings fish up from the bottom.
Scent glands located at the base of the tail are used for communication
Lifespan:
 In the wild: an average of 8-9 years
 In captivity: up to 21 years
Social Structure:
 Communicate with vocalizations, posturing, and scent marking
 Typically solitary, but will occasionally be seen in family groups or in groups of bachelor
males.
Ecosystem relationships:
 Predators: Large apex predators such as alligators, bobcats, large birds of prey, wolves
and coyotes.
 When not with young, or in open space, otters flee from predators, escaping through
speed and agility. When with young or cornered, however, otters will fiercly defend
themselves and their young.
 Interspecies competitors: Other fish-eaters such as herons and marsh birds, raccoons,
foxes and carnivorous fish.
 Role/ Niche: Important predators of fish and aquatic invertebrates. They help control
the populations of these animals, and serve as a food source for some apex predators.
Reproduction:
 Breeding season: Early spring in northern latitudes; winter in southern latitudes.
 Behavior:
o Males and females do not normally associate until the breeding season.
o Otters are polygynous, males mate with multiple females.
o Females care for the pups in a den near water.
 Gestation: Delayed implantation for 10-11 months, gestation lasts 5-7 weeks
 Number of offspring: 1-6 per litter, usually 3-4.
 Maturation:
o Young, called pups, are altricial and dependant on female for care
o Pups are blind for about a month after birth and are weaned at 3 months
o Pups become independent of their mother at about 6-12 months, and are
reproductively mature at 2-3 years old.
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North American River Otter
The Maryland Zoo
North American River Otter
Lontra canadensis
Activity:
 Active throughout the year
 Mostly nocturnal during spring, summer and fall – crepuscular during the winter
Other “fun facts”:
 River otter pups need to learn to swim. At first, they are wary of the water, so their
mothers will often simply push them in the water and they quickly learn.
 River otters will sometimes make loud snorting noises to signal danger.
Conservation Status and Threats:
 Listed on the IUCN Red List as Least Concern. However, in some states and localities
they are considered threatened.
 CITES: Listed under Appendix II. This makes the international trade of any part of this
species illegal without a permit.
 Threats: Over hunting, pollution and habitat loss are their largest threats.
o Historically, river otters had been over hunted and trapped for fur, especially in
the east and Midwest.
o Over hunting and pollution caused river otters to become absent through much
of their range until regulation and reintroduction helped re-establish and
stabilize their populations.
o Today, their threats vary based on their habitat. Coastal North American river
otters are highly impacted by disaster events such as oil spills. Inland, other
forms of pollution continue to be the largest threat to their survival.
 Conservation efforts:
o North American river otters are a conservation success story. Reintroductions
and strict regulation of trapping has helped stabilize their populations in parts of
their range that they were previously extirpated from, such as in the northeast
United States.
o CITES listing has greatly reduced the demand for their pelts.
o North American river otters are still rare or absent from much of the
southeastern United States. Research is being conducted to assess the impact of
pollution on these waterways and come up with effective reintroduction plans.
At the Zoo
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Here at the Zoo, 3 North American river otters are exhibited in the Maryland
Wilderness.
o Mary, female, born in 2000
o Piper, female, born in 2015 – Piper was orphaned as an infant in Louisiana and
was hand reared by the Audubon Zoo before arriving here at the Maryland Zoo
o Hudson, male, born in 2015 – Hudson was found orphaned as an infant in
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North American River Otter
The Maryland Zoo
North American River Otter
Lontra canadensis
Oregon and came to us from the Oregon Zoo.
What We Can Do
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Opt for fake fur over real fur when purchasing clothes or other products
o All of our shopping choices can have an impact on wildlife and the environment,
we can help move the market demand away from items that produce negative
consequences by making responsible, well-informed choices.
 Opt for recycled and/or local products
 Buy from companies that do not use animal-based products or testing
Educate friends and family about the importance of engaging with wildlife in a
respectful and responsible way. It can be very rewarding to observe wild animals, but
we should take care to avoid disturbing them and should never remove them from the
wild.
Make environmentally responsible lifestyle decisions to help conserve habitat –
conserve energy, reduce litter and pollution
o Get involved with your community: Support legislation that helps to protect our
watershed; participate in neighborhood trash clean-ups; work with your
community to organize a hazardous waste disposal day.
o Take steps to reduce water pollution in our watershed. Dispose of trash properly
and pick up litter.
o Use pesticides and other hazardous materials sparingly and dispose of them
properly to ensure that they do not end up in waterways.
Support the conservation efforts of local organizations like The Maryland Zoo as well as
organizations working in the field to protect wildlife and conserve habitat, such as the
Chesapeake Bay Foundation.
Additional Resources and References:
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Serfass, T. & Polechla, P. 2008. Lontra canadensis. The IUCN Red List of Threatened Species. Version
2014.3. http://www.iucnredlist.org/details/12302/0 . Downloaded on 1/24/15.
Serfass, T. L., Randall, L. P., Whary, M. T. and Brooks, R. P. 1993. River otter (Lutra canadensis)
reintroduction in Pennsylvania: prerelease care and clinical evaluation. Journal of Zoo and Wildlife
Medicine 24: 2840.
Serfass, T.L., Brooks, R.P. and Rymon, L.M. 1993. Evidence of long-term survival and reproduction by
translocated river otters, Lutra canadensis. Canadian Field Naturalist 107:59-63.
Otter Specialist Group: http://www.otterspecialistgroup.org/Species/Lontra_canadensis.html
Arkive: http://www.arkive.org/north-american-otter/lontra-canadensis/
Animal Diversity Web: http://animaldiversity.org/accounts/Lontra_canadensis/
National Geographic: http://animals.nationalgeographic.com/animals/mammals/american-river-otter/
National Wildlife Federation: http://www.nwf.org/wildlife/wildlife-library/mammals/north-americanriver-otter.aspx
Chesapeake Bay Program: http://www.chesapeakebay.net/fieldguide/critter/river_otter
Smith University: http://www.science.smith.edu/departments/biology/VHAYSSEN/msi/default.html
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North American River Otter
The Maryland Zoo