For the second time in two years, the Detroit Zoo is celebrating the birth of North American River Otters. Two male pups – born April 2, 2014, to mother Whisker, 11, and father Lucius, 8 – made their public debut today.

The female River Otter delivers a litter of one to six pups after an eight-week gestation period. At around two months, the young ones get their first swimming lesson when their mother pushes them into the water. Otters are natural swimmers and, with maternal supervision, the pups quickly catch on.

Photo credit: Jenny Miller

“Whisker is an experienced and attentive mother, guiding her pups through many new experiences – the most important of which is to encourage and reassure them as they strengthen their swimming abilities,” said Detroit Zoological Society Curator of Mammals Elizabeth Arbaugh.

The yet-to-be-named pups can be seen showing off their newfound aquatic skills at the Detroit Zoo’s Edward Mardigian Sr. River Otter Habitat. The naturalistic environment features a 5,900-gallon pool with a waterfall and waterslide, and the habitat is designed so that small children can view the otters at eye level as they swim.

The North American River Otter (Lontra canadensis) can weigh 20-30 pounds, and its slender, cylindrical body can reach 2-3 feet in length. The aquatic mammal sports short, dense, waterproof fur and profuse whiskers. The playful River Otter is swift on land as well as in the water, though its loping trot can look somewhat ungainly compared to its graceful slide through the water.

Once abundant in U.S. and Canadian rivers, lakes and coastal areas, River Otter populations have suffered significant declines as a result of fur trapping, water pollution, habitat destruction, pesticides and other threats. Today, they can be found in parts of Canada, the Northwest, the upper Great Lakes area, New England and Atlantic and Gulf Coast states.