Melanosuchus niger

The black caiman is the largest member of the alligator family and the largest predator in the Amazon basin. Adults are dark greenish-black, sometimes almost jet black, with grey to brown bands on the lower jaw and pale yellow or white bands across the flanks that are bold in young animals and fade slowly with age. The head is large and heavy with big brown eyes. Young black caimans can be told from spectacled caimans by their larger heads and dark jaws with three black spots, where the spectacled caiman's jaw is pale (Wikipedia, general species account).

It hunts mostly at night. As an apex predator it takes almost any animal it can overpower, and large males have more massive skulls and a stronger bite than females, so they probably take bigger prey. Breeding takes place in the dry season: the female builds a mound nest and guards the hatchlings, which gather in groups (pods) that can include young from other nests. It can be dangerous to people (Wikipedia, general species account; ReptTraits, Oskyrko et al. 2024).

Once common, the black caiman was hunted almost to extinction for its valuable hide, and was little studied until the 1980s. In Bolivia it lives in the north of the country (Wikipedia, general species account), and the Catalogue of Life records it from the Beni. On this guide it is a target species of the Pampas del Yacuma.