About River Otters

North American river otters are one of two otter species that can be found in the United States, and the only species found along the East Coast. River otters live throughout Canada and the United States in regions with healthy water systems. They can be found in rivers as well as ponds, lakes, marshes, bays, and even in the ocean. In California and Alaska, river otters sometimes share habitat with another species of otter, the sea otter. As carnivores and members of the weasel family, otters will eat fish and other small animals they can hunt near the water. 

In New York, river otters are often seen alone or in small groups. These groups will likely be a mother and pups, and sometimes groups of adults will travel together. Pups are born in late winter, usually in litters of two or three. After they’re born, their mother will find a mate to produce next year’s litter. Although gestation is only two months long, river otters will give birth up to ten months after mating due to delayed implantation. Pups are weaned after three months and they learn how to swim and hunt from their mothers. Otter pups grow quickly to adult size but can stay with their mother for a full year. 

River otters can have large ranges but they’ll visit the same areas of river bank repeatedly, sometimes for generations, to defecate and scent mark. These areas are called latrine sites. Otters can communicate using the scents they leave behind, and it’s believed that an otter can determine the age, sex, and reproductive status of other otters through the scents left behind at latrine sites. This ability helps otters find reproductive mates as well as avoid costly altercations with other adults. Latrine sites are excellent locations to set up trail cameras to study river otter behavior.