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. It is a very large species of crocodilian; males have been reported up to 6.8 m (22 ft 4 in) in the past, but such sizes do not exist today, 5.2 m (17 ft 1 in) being a more widely accepted maximum size. A large male today may attain 4.1 m (13 ft 5 in) in length and can weigh 380 kg (840 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in other crocodilian species. The coloration is light even in adults.
The biology of the Orinoco crocodile is poorly documented in the wild, mostly due its small population. It is thought to have a more piscivorous diet with an opportunistic nature, resulting in generalist predatory behavior. The Orinoco crocodile is an apex predator, and will take the opportunity to prey on a variety of birds, mammals, and reptiles, including caimans on occasion. The prey base is mostly made up of large predatory fish, challenging the general view by locals complaining about crocodiles hunting local fish to very low numbers. Despite its large size, the Orinoco crocodile rarely poses a threat to humans, despite several reports. Reproduction takes place in the dry season when the water level is lower. Orinoco crocodiles are hole nesters, just like the related Nile, freshwater, and saltwater crocodiles, and they dig holes in the sand to lay their eggs. The females guard the nests and young for several years.
This reptile is identified by the narrow snout, slopping upward at its tip. The body of the crocodile is covered with scales or scutes, ranging in shape and strength. The Orinoco crocodile is a very unusual reptile, which has no subspecies, meanwhile coming in 3 color types. These are: negro - when the skin of the animal is entirely dark grey; mariposo - when the crocodile is greyish-green with spots on dorsal part; and finally, amarillo - the most common type, exhibiting a light, tan color with dark, sparse patches all over the animal's body. When the crocodile is submerged, the nostrils, which are located at the end of the snout, remain above the water's surface, allowing the animal to breathe. The Orinoco crocodile has short and solid legs as well as long and powerful tail.
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 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.
Adult crocodiles are carnivorous, they mainly feed upon birds, fish and small mammals, including capybaras. Juveniles, on the other hand, tend to consume more insects, crabs, snail and fish.
These reptiles have 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 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 that 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 their population in the wild is unknown for today, varying from 250 to 1500 individuals. On the IUCN Red List, the Orinoco crocodile is classified as Critically Endangered (CR) species.
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.
