Adult Black Caiman
The black caiman (Melanosuchus niger) is a large crocodilian and the biggest extant member of the family, Alligatoridae. It is a carnivorous reptile that lives along slow-moving rivers, lakes, seasonally flooded savannas of the Amazon basin, and in other freshwater habitats of South America. It is a quite large species, growing to sizes of at least 5 m (16 ft) and possibly up to 6 m (20 ft) in length. As their name implies, the black caiman has a dark coloration, as an adult.
In some individuals the dark coloration can appear almost black. However they have gray to brown banding on the lower jaw. Juveniles have a more vibrant coloration compared to adults with prominent white to pale yellow banding on the flanks that remains present well into adulthood, at least more when compared to other species. The morphology is quite different than other caimans but the bony ridge that occurs in other caimans is present. The head is large and heavy; an advantage in catching larger prey.
The black caiman has dark-colored, scaly skin. The skin coloration helps with camouflage during its nocturnal hunts, but may also help absorb heat.
The lower jaw has grey banding (brown in older animals), and pale yellow or white bands are present across the flanks of the body, although these are much more prominent in juveniles. This banding fades only gradually as the animal matures. The bony ridge extending from above the eyes down the snout, as seen in other caiman, is present. The eyes are large, as befits its largely nocturnal activity, and brown in color. Mothers on guard near their nests are tormented by blood-sucking flies that gather around their vulnerable eyes leaving them bloodshot.
Egg Black Caiman
Hatchlings mostly eat small
fish, frogs and invertebrates such as, crustaceans and insects but as juveniles graduate to eating larger fish, including piranhas, catfish, and perch, which remain a significant food source for all black caiman, including adults. Various prey will be taken by availability, includes snakes, turtles, birds and mammals, the latter two mainly when they come to drink at the river banks. Mammalian prey mostly include common Amazonian species such as various monkeys, sloths, armadillos, pacas, agoutis, coatis, and capybaras.
Larger specimens can virtually take any South American terrestrial or riparian vertebrate unfortunate enough to encounter them. Large prey can include smaller species of caiman, deer, peccaries, tapirs, anacondas, giant otters, and domestic animals including pigs, cattle, horses and dogs. Where capybara herds are common, they are reportedly the most common prey item for mature adults.
Compared to the smaller caiman species, the black caiman more often hunts terrestrially at night, using its acute hearing and sight. As with all crocodilian species, their teeth are designed to grab but not chew, so they generally try to swallow their food whole after drowning it. Large prey that cannot be swallowed whole are often stored so the flesh will rot enough to allow the caiman take bites out of the flesh.