North American River Otters (Lontra canadensis) are fresh water animals and can be found throughout all of North America in rivers, streams, lakes and ponds. They are in the family Mustilidae, which also includes ferrets, skunks, weasels, and sea otters. North American river otters are not endangered and may even be considered a nuisance animal in some states where humans have encroached on their natural habitat. Today, river otters are seen more frequently in residential neighborhoods and other populated areas.
Adult river otters are basically solitary animals. There is not a strong bond between a male and a female, except for several months during the mating season. The basic family group consists of a female and her young; however, such families break up before the female gives birth again. Male river otters may or may not take part in the family group. What is interpreted as "play" behavior among otter pups is actually adaptive behavior that reinforces social bonds and encourages young river otters to practice their hunting and fishing skills.
The peak mating session for river otters is in March and April. During this time, river otters will travel more often and are more territorial. The total gestation period for a female otter is from 9.5 to 10 months which includes a period in which the embryo remains undeveloped. This holding period is called delayed implantation and it assures that the pup is born during the best time of the year for survival and allows the female to get into good physical condition. A female river otter may bear a litter each year. The average litter of river otters is two to four pups. Female otters will nurse their young for three to four months before they are weaned onto solid food.
River otters are territorial animals: they mark their home range with feces and urine, and they will spray an odorous liquid from scent glands located under the tail. They also rub their musky scent on logs, stones, or mounds of grass throughout their home area. Otters become especially territorial during the breeding session. Males will sometimes fight, competing for females, if mutual avoidance does not work. A river otter's home range includes the area in which the animal lives, reproduces, and generally satisfies its life requirements. The home range is usually 5 to 48 miles. Prey availability, habitat, weather conditions, the reproductive cycle, and human encroachment can influence the home range.
River otters are active predators whose diet consists mainly of fish. In the water, they will also prey on snakes, frogs, lizards, turtles, crabs, crayfish, salamanders, water beetles, mussels, snails, worms and small birds such as ducks. On land, river otters prey on mice, small rabbits, and ground-nesting birds and their eggs. It is also common for otters to eat grasses, pond weeds, algae, and blueberries. A river otter can eat 15% to 20% of their body weight daily, which is around three pounds of food. Otters do not store food for future consumption, and they will not kill more than they can eat.
Clearwater Marine Aquarium currently provides a home to six North American River Otters (Lontra canadensis). Since 1995, we have provided rehabilitative care for over 22 sick and injured wild river otters. Injuries and conditions have included parasites, distemper virus, anemia, arthritis, heartworms, heart disease, diabetes, puncture wounds, and injuries related to car collisions. To date, three otters have been rehabilitated and successfully released back into the wild, six otters have been relocated to other facilities within the United States, and five otters have remained as permanent residents at CMA. Webster, Cooper, Bella, Bogey, and a new not-yet-named otter are a very special part of our CMA family.
Otter Land