Fast Fact Attack: Endangered Species No. 57 – The Giant Otter

two otters by the river

Photograph from the Karanambu Trust

For decades these adorable otters were hunted for their fine silky pelt. Now, they are suffering from devastating habitat loss. Giant Otters are large, diurnal, extremely active, playful, sociable and very noisy. Despite their evil-looking eyes, they can be very friendly towards human beings; which clearly hasn’t protected them too well.

Giant otters are semi-aquatic land mammals who depend upon both land and water to survive. They can grow to six feet in length and weigh up to seventy-five pounds, making them the largest living otter, next to the sea otter. They have coats of dense velvety fur made up of short, waterproof guard hairs with some under fur. The colour ranges from reddish-brown to grey with irregular chest markings in a pale creamy colour. Some lack these markings. They have short, stubby legs with huge webbed feet. They have broad heads and stocky necks. The tail is dorsoventrally flattened and broad and powerful at the base. Highly adapted for swimming and diving, their sensitive whiskers aid prey location in unclear waters and their ears and nostrils close when entering the water.

They are capable of travelling long distances overland between bodies of water. They build camp sites on the river banks. Vegetation is pounded and trampled into the ground over an area of thirty by twenty feet. Latrines are dug around the perimeter. They maintain several of these camp sites in various locations. The camp sites are the sort of social club where they all gather to groom, play and relax. Dens are dug near the sites for sleeping and rearing cubs. Between the camp site and the dens the otters will have established a home territory which they will defend very aggressively against intruders.

They live in groups of up to ten individuals consisting of an adult pair (they are monogamous) and various generations of offspring.

The gestation period for a giant otter is between sixty-five and seventy days. Females will give birth to up to six cubs between August and early October. The young are altricial, meaning they are born helpless and need a lot of parental care. After four weeks the cub’s eyes will open and they will follow the mother around. After ten weeks the cubs will be able to eat fish, but will still depend on the mother’s milk until they reach at least sixteen or seventeen weeks. They grow quickly, and at ten months it is difficult to tell the cub from the adult. Unfortunately, there is a high juvenile mortality.

The estimated lifespan of a giant otter, in the wild, is ten to thirteen years.

Freshwater rivers, swamps, creeks and streams.
Scattered populations exist throughout the rainforests of South America.
What they eat
Fish, crustaceans and snakes, with the odd caiman now and then.  One giant otter will normally consume up to nine pounds of seafood in a day.
Up until the 1970s, this sleek river mammal was ruthlessly hunted for its silky pelt.   They are friendly creatures by nature, and will approach humans without fear.  This made them easy targets for ruthless, greedy hunters, and the population became decimated. Poaching still continues today on a lesser scale.  But, now there is an even greater threat; that of habitat loss.  Heavily degraded by logging, mining, exploitation of fossil fuels and hydroelectric power, river and land pollution, and over-fishing, their habitat is disappearing rapidly.  And, in some areas, cubs are being taken illegally and sold as pets. They need specialist care, which they are very unlikely to receive, and most will die through lack of it.  They have few natural predators.  Other threats include conflict with fishermen and diseases transmitted by domestic animals.
Status: Endangered
The giant otter (Pteronura brasiliensis ) is listed on the  IUCN Red List of Threatened Species  as Endangered.  It is also listed under  CITES Status: Appendix 1.   Within the next three otter generations, the IUCN predict their numbers will be reduced by half due to accelerating habitat destruction.  No-one knows exactly how many are left in the wild, but an estimation of one to five thousand individuals has been put forward.   There some kept in zoos around the world.   Efforts are being made to help the giant otter by way of education, research, awareness-raising programmes and management of protected areas.

“All that is needed for the forces of evil to triumph is for good men to do nothing”
Edmund Burke

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