Their eyes open at about 35 days of age. Brief trips outside the den begin at 10-12 weeks. Females do most of the work when it comes to raising the pups, but males help occasionally once the pups leave the nest. The young otters are coaxed into the water for the first time at about 14 weeks of age. They're weaned by 4 months of age, but often remain with their mother until the following spring.
Young females can breed at one year of age, but many wait until they're two.
Conservation Conserving wetlands and wooded areas along streams and rivers are top priorities. Reducing soil erosion and preventing fertilizers and pesticides from washing into streams are important measures, even where otters aren't likely to visit. For example, soil particles washed into a stream can settle when they reach slow-moving water, covering the rock, sand, or gravel that some fish need to lay their eggs and raise young. Fewer fish means less food for otters. Otters like to use dens and wetlands created by beavers.