By Annette J Beveridge
River contamination, habitat degradation and overfishing are all familiar stories but for the Giant River Otter, these pressures impact heavily. Found in the Amazon, Orinoco, and La Plata, there may only be 5,000 animals left in the wild. These low numbers are indicative of hunting where the otter pelt was once sought after. Fortunately, action taken in the 1970’s made this unappealing economically, but the slow reproductive maturity hinders the recovery process.
Giant River Otters are the largest of the mustelid family which includes ferrets and weasels, and they weigh a considerable 22 – 32 kg. They grow up to 1.8 metres in length. Often referred to as the river wolf, Giant River Otters are top predators with a streamlined body and webbed feet. They are agile swimmers, taking fish such as piranhas, Amazonian catfish but crustaceans and even snakes will make it onto the menu.
Their whiskers enable them to detect vibrations from prey underwater which helps them to find and consume up to 9lbs of food per day each.
Giant River Otters live in sociable family groups. This includes offspring from different breeding seasons and they make co-ordinated efforts to hunt together. This affords protection as they must share the river and compete for food alongside predators such as Black Caiman – a large species of crocodile.
Some good news
For the first time since the 1980’s, Giant River Otters have been spotted in the wild regions of Argentina. This may be a solitary individual or one from a small population that survived undetected. Local governments located close to the Bermejo River have confirmed their commitment to protecting this area from poaching.
Habitat loss, illegal mining, and over-fishing remain a threat but research into these animals may help. The People’s Trust for Endangered Species (PTES) and Adi Barocas in Peru are trying to identify what is happening currently. They will examine habitat, monitor inhabited riverbanks, and examine faeces to determine prey consumed to determine whether there is any contamination. Human disregard and disturbance have impacted the Giant River Otter populations but these animals play a vital role influencing the aquatic ecosystem so hopefully, positive human intervention and science can lead the way to their recovery.