Northern River Otter
The short, dense fur is dark brown, with the face, chin, and throat having a grayish sheen. Adults are 0.9 - 1.2 m (3 - 4 ft) in total length and weigh 5 - 10.4 kg (11 - 23 lbs). The River Otter is long and cylindrical in body shape. It has short legs and a short, thick neck. The snout is short and broad. The ears are small, and the tail is long and thick at the base. The feet are webbed.
River Otters mate in late winter and early spring. After mating, a delay of 290 - 380 days occurs before the actual development of embryos begins. Gestation takes 60 - 63 days once implantation of the embryos in the uterus occurs. In March or April, from 1 - 6 young are born in a leaf- and grass-lined den constructed in an old muskrat lodge, abandoned burrow, or hollow tree close to a water source. The young, called kits, are developed enough to leave the den with the female at 10 - 12 weeks of age. The female River Otter teaches the young to swim and hunt for food. The male may assist the female in caring for the young once they leave the den. Young remain with the female until the breeding season after their birth. A River Otter is capable of breeding once it reaches two years of age.
The River Otter ranges widely along rivers, streams, swamps, and marshes. An individual otter may move from 77.2 - 96.6 km (48 - 60 mi) along a waterway in a season, but the average is from 4.8 - 16.1 km (3 - 10 mi). Throughout its home range, a River Otter has "pulling out spots" where it makes "scent posts" by gathering and piling up water-logged leaves, sticks, or aquatic plants, and marking them with feces and urine. A scent post informs other otters of the River Otter's presence, but otters do not defend territories against one another. The River Otter is an extremely intelligent animal and exhibits a high level of curiosity. When encountered along a waterway, it will stop and crane its neck to look at a human, if the person is moving slowly and is not acting in a threatening manner. Otters have a playful nature and will play both by themselves and with other otters. They will make slides on mud banks into the water and use them over time to the point where they become deep troughs. The River Otter is most active from dawn to midmorning and again in the evening. It forages for foods such as rough fish, crayfish, mollusks, crabs, amphibians, rodents, birds, eggs, and small reptiles. Contrary to popular opinion, the River Otter does not affect the quality or quantity of sport fish populations. If anything, it contributes to a healthy fish population by culling out the weak and sick individuals. The River Otter has few natural predators, but there are reports of it being preyed upon by American Alligators, Bobcats, and Coyotes. River Otters have lived for 20 years in captivity, but 5 - 7 years is the average in the wild.
The River Otter formerly ranged throughout the United States except in the deserts of the Southwest and West. Its numbers have been greatly reduced through loss of habitat and through hunting and trapping in most of its former range. In the right habitat, River Otters can be found throughout Georgia.
The River Otter is considered a fur-bearer. In Georgia, the trapping season runs from December through mid-February.
No other large aquatic mammal in North America looks like a River Otter. Both the Beaver and the Muskrat are stocky and squat in build, whereas the River Otter is long and slender.