Oxbow-lakes are old remnant river courses, cut-off from the main river by the effects of erosion and the constant shifting of river canals. On the Manu river we can find several Oxbow-lakes, two of them are frequently visited by us: Salvador being the largest one and Otorongo which allows a relaxing view of the forest and marshland from a catamaran.

A lot of interesting animals live in and around these lakes: Black Caiman, Boa, a multitude of bird life, monkeys and the endangered Giant Otter. Beneath the surface live many hundreds of fish species, many small and colorful, others large and whiskered. Several species of piranhas also live in these lakes.

Giant Otter: Occupying a top position in the food pyramid among Manu's lakes is the Giant Otter (Pteronura brasilensis), an aquatic mammal that can measure up to 6 feet (1.8 meters) in length and weight up to 70 pounds (32 Kilos). Giant otters are highly social animals, living in closely-knit family groups. They often hunt communally using their whiskers to detect fish in the murky lake depths. Adult otters commonly eat up to 10 pounds (4 kilos) of fish a day.

Giant Otters have been heavily hunted in the last decades, for that reason is an endangered specie with not many individuals left in the world. Nevertheless on the Manu River and the Oxbow-lakes of the Reserved Zone we have the biggest population of otters in the rainforest.

Giant Otters are a very territorial animals, specially if their habitat is a fairly extended lake such as Salvador and Otorongo, for that reason the chances of spotting them are quite high.

If a group is spotted try not to make any noise or hasty movements. They are usually very inquisitive creatures and will often approach the catamaran to within 30 or 40 meters.