River otters are typically 31 lbs and 53 inches long, with brown fur covering their bodies. They breathe through lungs and are warm-blooded mammals, giving birth to litters of 2-3 pups. Otters travel swiftly by walking or swimming and live throughout the US except the Florida Keys. Though some habitats experience snowy winters, otters do not migrate or hibernate. They are carnivores that eat meat and protect themselves by fleeing, coming onto land, or taking refuge under their natural predator avoidance. River otters are not currently endangered.