An aquatic mammal once common throughout all of North America is the North American River Otter (Lantra Canadensis).
Although harvesting of furs over history has limited their territories, there are still plenty of otters around. Observed year-round in every county in South Carolina, the winter months in the Lowcountry are a great time to see them out in the salt marshes and estuaries.
Preferring slow-moving water and ample covering for protection, otters are most active at night. In the winter months, they become diurnal and are often seen during the day.
Well-designed as aquatic mammals, River Otters have whiskers used to locate food in murky waters.
They are able to hold their breath for about four minutes, an advantage when hunting small fish, crustaceans, mollusks, amphibians and snakes. Very oily waterproof fur, a distinct shape, webbed feet and large tapered tails gives them agility, power and speed while swimming. Specially-formed ears and noses close when diving. Otters are able to see clearly underwater due to a nictitating membrane, which also protects the eye from debris. While not as agile on land, they have a very acute sense of hearing and smell.
In late winter and early spring otters breed.
Reaching maturity at the age of two, females have very a unique reproduction cycle. After copulation, an embryo may stay within a female for up to eight months before gestation. Since gestation takes about 60 days, babies are born 10 to 12 months after copulation.
Females look for a den in order to give birth to their young (two to four kits at a time). Usually females find an already established, but abandoned, den in a tree hollow or old beaver dam. Born with fur, the kits’ eyes open within three weeks. They will be playing in the water within eight weeks of birth.
The females teach their young how to swim and forage for food. Males will not aid in the rearing of young. The kits will stay with their mothers six months to a year.
The North American River Otter’s life span is approximately 15 years.
Commonly, otters in groups. Generally, female otters live in family groups with their young. Sometimes, female otters help with other otters from other families. Male otters sometimes live in groups of up to 17 individuals.
American Indians hunted river otters for their fur. In the 1500s, the settlers hunted them for the same purpose. Today, North American River Otters are no longer a threatened species. However, pollution, habitat destruction and development are all factors affecting otter populations.
With minimal hunting taking place in South Carolina, the otter population is stable here. Take time to observe these curiously playful creatures.
By Kathleen McMenamin, Master Naturalist