This reptile is a crocodilian that can reach an astonishing six meters in length. Caimans live in the still waters of oxbow lakes and rivers and are very good swimmers, with long, slender bodies and powerful tails that propel them through the water. They crush their prey with their powerful jaws and, along with their staple diet of fish, will eat anything they can get their jaws on, including capybaras, juvenile otters, birds, insects, and mollusks.

Caimans may be such fierce predators because they have such a hard time growing up. The eggs are eaten by snakes, fish, and hawks. After hatching, baby caimans hide in the water grass, coming out only at night, to avoid being eaten by a turtle, otter, or wading bird. A very small percent of caimans survive the ordeal.

Caimans can be easily spotted by the red reflection of their eyes in a flashlight beam, a common night activity at many lodges. With a fast hand jab into the water, most Amazon guides are capable of pulling a juvenile caiman up to a half meter out of the water for inspection.

There are four species of caiman in Peru: the dwarf (1–5 meters), the smooth-fronted (two meters), the spectacled (five meters), and the black (up to six meters). This last, rarest of all, has black marks, a spiky tail, and a short snout. After being hunted relentlessly for their skins in the first half of the 20th century, the Amazon’s caiman population is a fraction of what it was in 1900.