River and waterway pollution and habitat destruction are major factors affecting the river otter population.
When it nears time for an otter to give birth, she begins searching for a den. Instead of digging their own dens, otters often rely on the dens of other animals. Once born, otter pups begin playing at 5-6 weeks old. Female otters use play to teach their cubs survival skills. Fun activities like sliding through mud and snow teach young pups methods of evading predators.