American Crocodile

## Description

The American crocodile (Crocodylus acutus ) is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida and the coasts of Mexico to as far south as Peru and Venezuela.

The habitat of the American crocodile consists largely of coastal areas. It is also found in river systems, but tends to prefer salinity, resulting in the species congregating in brackish lakes, mangrove swamps, lagoons, cays, and small islands. Other crocodiles also have tolerance to saltwater due to salt glands underneath the tongue, but the American crocodile is the only species other than the saltwater crocodile to commonly live and thrive in saltwater. They can be found on beaches and small island formations without any freshwater source, such as many cays and islets across the Caribbean. They are also found in hypersaline lakes; one of the largest known populations inhabits Lago Enriquillo in the Dominican Republic.

The American crocodile is 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). On average, mature males are more in the range of 2.9 to 4.1 m (9 ft 6 in to 13 ft 5 in) in length weighing up to about 400 kg (880 lb). As with other crocodile species, females are smaller, rarely exceeding 3.8 m (12 ft 6 in) in length even in the largest-bodied population.

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

This reptile is one of the largest crocodile species in the world. 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. Unlike other species of crocodile, these reptiles are not green. The body of American crocodile 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 armour, formed by so-called osteoderms or plates, which are more scattered in American crocodile, 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.

## Distribution

The 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 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. The American crocodiles are aquatic animals, living in freshwater environments such as rivers, reservoirs, lakes as well as estuaries and swamps.

## Behavior

The American crocodile is most active at night. The animal spends the greater part of the evening submerged in water, which cools slowly, keeping the animal warm for a long period of time. The American crocodile is not a social animal. This reptile prefers living alone and typically avoids disturbances. However, these crocodiles occasionally socialize, usually at sunset, when the temperature of their body is low. When facing danger, the animal can be extremely aggressive. At the dry season, the crocodiles become inactive: they do without food, spending their time buried in the mud. These reptiles love sunbathing, just like alligators. When having sunbaths, the animals gape, exposing themselves to the sun with their open mouth, which helps them regulate their body temperature.

## Diet

This reptile is a carnivorous animal. The diet of the American crocodile 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. At 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 on 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. The American crocodiles are sexually 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 loss of their habitat as a result of human development.

### 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 of 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 of the area.

## Fun Facts for Kids

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 salt content of the ocean; they can only drink from the freshwater layer upon the surface of the ocean water.

A 450 kg (992.1 lb.) crocodile can withstand extremely long intervals between meals. Compared to other reptiles, 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'.