These animals are voracious. They can consume up to 3 kg of fish per day. Their size is a factor in this appetite, as adults can reach 2 meters in length and weigh up to 35 kilograms. Occasionally, they vary their diet to include crabs, amphibians, small mammals, mollusks, birds, and even caimans, snakes, and turtles. With membranes between their toes, they swim effortlessly through the waters. Diurnal by nature, they build shelters among roots and fallen trees in rivers to sleep at night. They live in groups and use their collective strength to ward off predators. They often emit sounds to communicate with each other and to scare off jaguars. In recent years, the giant otter population has undergone a dramatic decline and is now considered vulnerable by ICMBio, Brazil’s Ministry of the Environment. The main threats include water contamination and habitat destruction.