Giant river otters engage in puzzling behaviour

The Pantanal, in Brazil, is the largest tropical wetland area in the world. It is also the world's largest flooded grasslands. These giant river otters live in the Pantanal. They were recorded as they seemed to be hunting and playing in an isolated spot along the river where they live. They climbed in and out of the water and patted the mud with their paws, stomping all four feet as they did so. One of them urinated in the mud and then seemed to be spreading the mud around the area on the bank.
Although highly social, giant river otters are also highly territorial. This puzzling behaviour makes sense because they have scent glands on their paws, as swell as anal glands. The otters pat the mud and shove it around to make scent mounds. They squeeze their anal sacs to create a scent marker to be used in communication with other otter families. They are announcing their dominance in the areas that they mark. Urine and feces are also deposited in prominent bathroom or sleeping areas along their territory.
The river otter can reach a length of 1.8m, or nearly 5.5 feet. They can weigh as much as 32kg or 71lbs. Enormous animals with formidable teeth, they are one of the few species of animal in the Pantanal that commands the respect of the jaguar. Jaguars are the undisputed top predators in these jungles and wetlands but a family of giant river otters, in cooperation, can fend of even the most determined jaguar. Their agility in the water and their ferocious bites make them more trouble than they are worth. For this reason, they are often referred to as the "river gangsters".
These otters were also seen hunting for catfish in the murky river. They use their whiskers while underwater to sense their prey in areas with poor visibility. Giant river otters are an endangered species due to excessive hunting as well as habitat destruction.