Northern River Otter

Feb 25, 2010

By Steve Blight

Note the webbed feet on this otter.Photo Dave Pape

Just before the big rainstorm in the last week of January, I was out exploring the winter landscapes in the Sharbot Lake area and was surprised by the richness of the traces of local wildlife. January didn’t see much snow this year, and there had been a significant accumulation of tracks and trails in the thin layer of light snow on top of the frozen surface. Traveling up and down the creeks and across the beaver ponds, taking care not to fall through the ice, gave me a wonderful chance to follow the travels of one of my favourite animals, the Northern River Otter.

In winter, otters normally travel across snowy landscapes by an alternating series of bounds and slides. The slides are quite easy to identify, created by the animals when they leap onto slippery surfaces with their front legs tucked close to their bodies for a streamlined toboggan ride. Look for tracks and slides going in and out of open water near beaver dams and lodges or patches of faster-moving water.

Otters are active all winter, and are usually found year-round near water where they search out fish, crayfish, and overwintering frogs and turtles. In summer, otters will also consume birds, aquatic insects and small mammals, including young muskrats and beavers. Otters appear to be playful, and some sources suggest that this is because they are such good hunters that they often have time to spare when prey is plentiful.

Otters are not small animals – an adult can weigh up to 11 kilograms (about 25 pounds). This is a few pounds bigger than my full-size cat, who weighs in at about 18 pounds. Compare this to the size of the otter’s close relatives the Mink at about 1.4 kg (3 pounds) or the Fisher at 5.5 Kg (12 pounds). Dark brown above and paler below, adult otters can measure up to 1.4 meters long (about 4.5 ft) from nose to tip of tail. They are relatively long-lived, reportedly living up to 15 years in the wild and as long as 25 years in captivity. They are extremely well adapted for a semi-aquatic life, with streamlined bodies, rudder-like tails, webbed toes, and ears and nostrils that can be closed to shut out water. Excellent swimmers, otters are believed to be able to hold their breaths for up to 5 minutes.

Unlike most members of the weasel family, otters are social animals. Life is loosely organized around family units and otters are often seen in small groups. Their permanent dens are commonly located in banks, and usually have both underground and underwater entrances. In March or April, the female gives birth to one to six, fully furred, blind young in a separate den, frequently built in an abandoned beaver, muskrat or groundhog den. Within three to four months, the young otters leave the den and are independent at six to seven months. Otters are capable of reproducing at about 2 years of age.

In the past, the Otter’s thick, lustrous fur led to widespread trapping that greatly diminished its numbers across North America. Trapping has been reduced and otters seem to be recolonizing areas of the continent where the species had been absent for decades. In the Land O’Lakes area, otters are relatively common thanks mainly to the abundance of clean, productive water bodies and extensive forested areas. Other than humans, otters have few predators in water, but on land youngsters can fall prey to bobcats, coyotes or wolves.

Winter in our part of Ontario can seem long, but it also provides a yearly opportunity to renew old acquaintances with a fascinating resident of the Land O’Lakes area, the Northern River Otter.

Please feel free to report any observations to Lorraine Julien at This email address is being protected from spambots. You need JavaScript enabled to view it.  or Steve Blight at This email address is being protected from spambots. You need JavaScript enabled to view it.