The Otters in this gallery are River Otters, all photos were taken in the Lamar River in Yellowstone National Park. In addition to being related to other Otter types, Otters are also related to weasels, polecats and badgers. The river otter grows to 3 to 4 feet in length and a weight up to 30 lbs. The otter is a simi aquatic animal whose diet consists mainly of fish, but they will also consume small birds and mamals. As they often live in cold climates they have an accelerated metabolic rate which along with their fur allows them to stay warm. This high metabloic rate means that they must consume significant ammounts of fish every day (aprox. 20% of body weight). The typical animal spends 3 to 5 hours a day hunting. The male is called a dog while the female is a bitch. A group of Otters is a bevy and they live in a holt. You're now ready for trivia pursuit.