The Orinoco crocodile (Crocodylus intermedius) is a critically endangered crocodile. Its population is very small, and they can only be found in the Orinoco river basin in Colombia and Venezuela. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. Despite its large size, the Orinoco crocodile rarely poses a threat to humans, despite several reports.
The Orinoco crocodile can be recognized by its relatively long snout, which is narrower than that of the somewhat similar-looking American crocodile. This species generally has a pale tan hide, though at least three coloration variations are known, with some almost completely yellowish, and some a dark brownish-gray. The skin can change color over long periods of time; this phenomenon has been recorded in other species that can gradually change the amount of melanin in their skin. These crocodiles have dark-brown markings, which present as more pronounced bands in younger specimens and as scattered markings on mature ones.
Orinoco crocodile occurs in Colombia and Venezuela, being found in the water and quiet lagoons of the Orinoco River basin. As the rainy season comes, the water level rises, and the crocodiles escape to nearby ponds and lakes, staying there until the water recedes.
The Orinoco crocodiles are social animals, living in a dominance hierarchy. These reptiles have a communication system with well-developed responses. Usually, these crocodiles are very slow except with feeding. They feed at night in the water, having coordinated feeding behavior. They approach the river bank to catch terrestrial animals. The Orinoco crocodiles are excellent swimmers. When in water, they propel themselves by their webbed feet as well as power thrusts of their tail. These reptiles (particularly large males) can sometimes be extremely aggressive. During the dry season, they often gather into large groups and travel over land in search of suitable aquatic habitat; when the section of the river within their home range dries up, the animals back away into burrows.
Orinoco crocodiles are apex predators and virtually any animal living within their range could be considered a potential meal. They mainly feed on birds, fish, and small mammals, including capybaras. Juveniles, on the other hand, tend to consume more insects, crabs, snails, and fish.
These reptiles have a polygynous mating system, where one male mates with a number of females. The mating season occurs in January-February, matching the dry season. As the water level decreases, water-free sand banks appear where the females dig nests, laying from 15 to 70 eggs with an average of 40. The eggs are incubated for about 70-90 days, usually hatching by the beginning of the rainy season. When the hatching time approaches, the young appear, giving out chirping sounds. The crocodile mother hears the call of her offspring and helps them come out, introducing the hatchlings to the water. For the first 1-3 years of their lives, the young are protected and cared for by their mother.
Currently, the Orinoco crocodile is hunted for its meat and teeth which are used for medical purposes. In certain areas of their range, the animals are killed by local people, suffering from destruction of their natural habitat as well as collection of their eggs and juveniles. The Orinoco crocodile also competes with the spectacle caiman that inhabits the same area.
The exact number of this species population in the wild is unknown today, varying from 250 to 1,500 individuals. Currently, the Orinoco crocodile is classified as Critically Endangered (CR) on the IUCN Red List, and its numbers today are decreasing.
Due to feeding upon a wide variety of animals, these predators play an important link in the food chain of their habitat by balancing and maintaining the health of the local ecosystem.
