American Crocodile

## Description

The American crocodile (Crocodylus acutus) is the most widespread of the four extant species of crocodiles from the Americas. It is also one of the largest crocodile species. Males can reach lengths of 6.1 m (20 ft 0 in), weighing up to 907 kg (2,000 lb). Like any other large crocodilian, the American crocodile is potentially dangerous to humans, but it tends not to be as aggressive as some other species.

## Appearance

Unlike other species of crocodile, American crocodiles are not green. Their body is either tan grey or olive grey in color, covered with darker patches. Their belly is white or yellowish. The back of the crocodile is partially covered with bony armor, formed by so-called osteoderms or plates, which are more scattered in American crocodiles, than in other crocodile species. The top jaw has pointed teeth, having a conical form, and interlocking with the teeth on the bottom jaw of the animal. They have large fourth teeth on both sides of their bottom jaw, which are prominent even when the jaw is closed. The irises of their eyes are silvery in color while the pupil has a form of a vertical slit, helping the animal see well in low lighting conditions.

## Distribution

American crocodiles are found on Cape Sable as well as along Lake Worth and the southeastern coast of Florida. The area of their distribution includes both the Atlantic and Pacific coasts of southern Mexico, stretching to Peru and Venezuela in South America. In addition, this reptile inhabits many Caribbean islands, including Jamaica, Cuba, Hispaniola, and Grand Cayman. They live in freshwater environments such as rivers, reservoirs, lakes as well as estuaries, and swamps.

## Behavior

American crocodiles are most active at night. They spend the greater part of the evening submerged in water, which cools slowly, keeping them warm for a long period of time. These are not social animals. They prefer living alone and typically avoid disturbances. However, these crocodiles occasionally socialize, usually at sunset, when the temperature of their body is low. During the dry season, they become inactive: they do without food, spending their time buried in the mud. They love sunbathing, just like alligators. When having sunbaths, they gape, exposing themselves to the sun with their open mouth, which helps them regulate their body temperature. When facing danger, American crocodiles can be extremely aggressive. Unlike other crocodiles, they use acoustic signals to communicate. Crocodile communication is centered on short-distance communications during courtship and hatching.

## Diet

American crocodiles are apex predators, and any aquatic or terrestrial animal they encounter is potential prey. Their diet mainly consists of small mammals, fish, frogs, birds, and turtles. Hatchlings forage on land, feeding mainly upon insects. Meanwhile, young crocodiles tend to consume aquatic invertebrates and small species of fish.

## Reproduction

These reptiles have polygynous mating system, where one male mates with a number of females. During the mating season, the animals become very territorial. Usually, males compete with each other for mating rights. During the breeding season, which lasts from April to May, females lay about 30-60 eggs. The eggs are typically laid in a hole or in an elevated place. As the hatching time approaches, the female visits the nesting site more and more frequently, until, in about 9-10 weeks after being laid, the eggs finally hatch. The female helps the young hatch out of the eggs and later accompanies the hatchlings on their way to the water. Soon the young disperse, leaving the hatching site and living independently. American crocodiles become reproductively mature at the age of 8-10 years.

## Population

### Population threats

The species is exposed to illegal hunting and poaching due to its hide. The American crocodile also suffers from the loss of their habitat as a result of human development, pollution, and commercial farming.

### Population number

On the IUCN Red List, the American crocodile is classified as a Vulnerable species. The overall number of their population is unknown, but presently increasing. However, the total estimated population in Mexico, as well as Central and South America varies from 1000 to 2000 individuals.

### Ecological niche

The American crocodile is the top predator in its range. Due to preying on a wide variety of animals, this reptile controls populations of these species. In addition, the leftover food of the American crocodile is a source of food for other animals in the area.

## Fun Facts

These animals tend to swallow stones, which help them digest food as well as control buoyancy in the water.

Adult crocodiles possess special salt glands on their tongue, filtering the salt and allowing them to drink ocean water. Juveniles, however, are not able to digest the salt content of the ocean; they can only drink from the freshwater layer on the surface of the ocean water.

A 450 kg (992.1 lb.) crocodile can withstand extremely long intervals between meals. Compared to other reptiles, the hearts, and brains of these animals are far more developed. Also, the ectothermic metabolism of their bodies is very beneficial to these reptiles.

The males of these crocodiles use various vocalizations as well as body movements such as tail and head-slapping, as a way of communication during the courtship or in order to defend the territory. In addition, males are capable of emitting infrasonic sounds under the water, which produce ripples on the surface.

The largest American crocodile was a male, found in the Tarcoles River (Costa Rica). The body length of this reptile was as much as 5.5 meters (18 feet).

While the Old World crocodiles usually depend on birds to clean their bodies from parasites, the American crocodiles allow small fishes to clean their bodies.

The heart of this reptile has 4 chambers, like that of birds.