Amazing River Otters

Did you know that a group of river otters is known as a “romp?”  If you head outdoors this time of year, near open water, you have a good chance of seeing some of these playful creatures. On a recent walk on the Discovery Center Big River Trail, Assistant Director Azael Meza came across one playing on the ice and water of the Manitowish River.  The temperature was 0 F. As humans we would not dare go outside without our full winter gear on, let alone swim and play on the ice! So how do these animals manage to stay warm and survive these frigid lakes and rivers?  River otters are well prepared to live in the northern Wisconsin climate, and to be active year round. They have incredibly dense fur containing nearly 160,000 hairs per square inch. This creates a waterproof barrier that keeps them warm in the coldest water.  Like beavers (although unrelated, as beavers are rodents and otters are in the weasel family), they have been known to swim beneath ice and use trapped air bubbles to breath, if that’s not an option, they can hold their breath for up to 8 minutes! These amazing animals are fully adapted to their riparian environment. River otters have webbed back feet that help to propel them up to 12 mph in the water and their body shape is long and thin, which makes them extremely hydrodynamic.  Their close relatives, sea otters, have the densest hair of any animal, with some of them having over 1,000,000 hairs per square inch!  Visit the Big River Trail at the Discovery Center all winter to see what you can discover!

by Licia Johnson, Discovery Center Naturalist 

River Otter  Lutra canadensis
Photo by Azael Meza