|North American River Otter
Lontra canadensis; aka Northern
River Otter, River Otter, Common Otter
Built for an aquatic lifestyle, the river
otter has a long, streamlinded body, short,
powerful limbs, and webbed feet. The nostrils and
ears can be closed when the animal is underwater.
To propel itself through the water, this species
primarily combines hind-limb paddling with
vertical undulations of its remarkably long,
tapering tail. It is capable of staying submerged
for up to 8 minutes, and can dive as deep as 60
feet. Although it is built for the water, the
river otter is capable of reaching speeds of up
to 18 miles an hour on land. Long whiskers help
the river otter detect prey underwater.
The thick, velvety fur is black, reddish or
gray-brown on the back and light or gray-brown on
the belly. The throat and cheeks are usually
golden brown in color. The river
otter can reach a length of 3-4 feet long
(including the tail), a height of 10 inches at
the shoulder, and a weight of 11-23 pounds. Males
tend to be about 5% larger than females.
Distribution and Habitat
North American river otters are found
throughout Canada and much of the eastern and
western United States, as well as in the delta
areas of the Rio Grande and Colorado rivers of
Mexico. They will live just about anywhere there
is a permanent food supply and easy access to
water, whether it be freshwater or coastal marine
habitat, warm or cold water, as long as it is
Although fish makes up the
majority of its diet, the river otter will take
just about any kind of aquatic animal available,
as well as birds and bird eggs, small terrestrial
mammals and reptiles, and even the occasional
A quick lunge from a position of ambush is the
most commonly employed hunting method, but
prolonged chases do sometimes occur. Prey is
eaten immediately after capture, usually in the
water, although larger prey may be eaten on land.
Mating occurs in late winter
and early spring. Although it is known that males
often breed with several females, it is not known
whether there is any competition for mates or
whether the females have a "say-so" in
which males they mate with.
Gestation only takes about 2
months, but since river otters practice delayed
implantation births don't generally begin until
March and April (10 to 12 months after mating).
One to five pups are born in a den near water.
They have fur but are otherwise helpless. The
pups' eyes open at about one month, they are
weaned and taught to swim at about 2-3 months,
and will stay with the mother until about their
tenth month. Males take no part in the rearing of
Sexual maturity is reached by
the third year, and maximum lifespan in the wild
is about 9 years.
Other Habits and
Although they tend to live
solitary lives, river otters can often be seen
socializing in groups comprising dozens of
individuals. When socializing, river
otters use a wide variety of sounds to
communicate with each other.
River otters are very playful, exhibiting
behaviors such as mud/snow sliding, burrowing
through the snow, and waterplay. Many
"play" activities actually serve a
purpose. Some are used to strengthen social
bonds, to practice hunting techniques, and to
scent mark. North American river otters get their
boundless energy from their very high metabolism,
which also requires them to eat a great deal
during the day.
River otters maintain fairly
large home ranges but are only slightly
territorial, prefering avoidance over territorial
Dens have underwater entrances and a tunnel
leading to a nest chamber that is lined with
leaves, grass, moss, bark, and hair.
River otters normally hunt at night, but can
be seen any time of the day.
genus & species Lontra canadensis
Animal Diversity Web http://animaldiversity.org/accounts/Lontra_canadensis/
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