Scientific Name: Pteronura brasiliensis
The giant otter is one of the few species of carnivore whose nose is completely covered with fur.
As you would guess from the name, the giant otter is the largest otter species. Sea otters can be a little heavier but have shorter and wider bodies than the giant otter.
Life Along the River
Giant otters are monogamous, living in small family groups with offspring that may stay with the family for two or three years before becoming mature enough to go off on their own. From one to five cubs (usually two or three) are born after a gestation period of 65-70 days. The cubs are born in an underground den close to the water’s edge. They are fully furred but helpless at birth. They are taught to swim at about two months. Cubs grow to adult size in about ten months.
Otters are active during the day. They are gregarious and often hunt in family groups; and share a burrow at night. Adults have few predators other than humans. Otters have a high juvenile mortality rate, but if they reach adulthood, they can expect to live 10-13 years. The family group defends a territory around a central “camp site” that is strongly scent marked. They are extremely vocal with a number of different calls, some of which can be heard underwater. Their size and enormous appetites have earned giant otters a local name that translates to “river wolves.”
The giant otter is classified as Endangered by the International Union for Conservation of Nature (IUCN). Hunting otters for pelts is now illegal, but laws against poaching are difficult to enforce in the areas where they live. They are also threatened by chemical pollution in the water. The runoff from farms, oil drilling and mining operations threatens them. Deforestation has degraded the otter’s habitat.
Giant otters live in slow moving water, streams, lakes and swamps in the Orinoco, Amazon and La Plata river systems of South America. They range from northern Argentina to Colombia and Venezuela, east of the Andes Mountains. They prefer areas with gently sloping banks and overhanging vegetation.
The otter’s primary food is fish, such as catfish and perch. They will also eat crustaceans, snakes and small caiman. In turn, large caiman sometimes eat small otters! Small fish are eaten in the water, while larger ones are carried to shore. The front feet have five digits, each with a sharp claw for handling slippery fish. Otters are active animals with a high metabolic rate and need six to ten pounds of food every day.
The head-body-tail length of an adult giant otter can be over six feet. Adult males weigh up to 70 pounds, females are a little smaller. They have many adaptations for life in the water. The toes are fully webbed. Their long, torpedo shaped bodies move through the water with minimal resistance. A powerful laterally flattened tail provides swimming power. There are numerous vibrissae (sensory whiskers) on the muzzle and head to help find prey in murky water. The fur is very dense and water repellant.