Northern River Otter Lontra canadensis
Northern river otters are a relatively large mustelid, weighing from 7-14 kg and lengths from 90-135 cm. They live near aquatic environments, foraging mostly on small fish, but will consume invertebrates, insects, small mammals and birds. They are well adapted to their aquatic lifestyle, having thick layers of fat, sleek, oily fur and large lungs that can allow them to dive for up to four minutes. Males are generally larger than females, and their breeding season begins in February. River otters have home ranges or territories but they are flexible, overlapping and undefended, largely due to prey distribution. Males and females overlap in territories, but males home ranges tend to be much larger than those of females.