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Giant otter eating © Torsten Karock

Giant otters are an endangered species.

Endangered Giant Otter Threatened by Widespread Habitat Degradation

Known in parts of South America as the “river wolf,” the giant otter is indeed giant, reaching a body length of over 5 feet with a tail sometimes longer than 27 inches. It is not, however, the heaviest otter. Weighing about 70 pounds, giant otters may weigh less than some sea otters.

Their velvety fur is reddish-brown with cream on the throat and chin, and their long whiskers are thought to be very sensitive to help in hunting.  Found in rivers, lakes, streams and swamps in South America, giant otters live in territorial groups averaging 2-12 otters. Groups of up to 20 individuals have been observed in good habitat. 

Mostly active during the day, giant otters eat fish, fish eggs, frogs, small caimans, aquatic mammals and even anacondas hapless enough to be caught. They have dens in riverbanks or under tree roots where they bear litters, usually 1-2 young per female after a 9-10 week gestation. After about 13 weeks, cubs are able to swim and fish by themselves, but they usually remain with their group for 2-5 years, helping care for the newest young. Adult males and females will maul fish and present them half-dead to cubs. 

Once hunted for pelts, the giant otter is now threatened by widespread degradation of its native habitat by mining, damming, logging and over fishing. The IUCN lists the species as Endangered and predicts that global populations may halve in the next 20 years if present trends continue.