Crocodylus niloticus

Description

The largest crocodilian in Africa, the Nile crocodile can be up to 20 feet long and weigh up to 1,650 pounds; males tend to be larger than females.

Like all crocodilians, the Nile has a streamlined body, a long, powerful tail, webbed hind feet, and long, powerful jaws. Its eyes, ears, and nostrils are located on top of the head, allowing it see, hear, and breathe while lying just below the surface of the water.

The Nile crocodile has quick reflexes and is a surprisingly fast runner on land, but can tire quickly.

The body of the adult is a grey-olive color, with a yellowish belly, while the juvenile is more greenish or dark olive-brown, with black cross-banding on the tail and body, which becomes fainter in adults.

Distribution and Habitat

The Nile crocodile is found throughout most of Africa, except for the Sahara, and including Madagascar. It lives alongside rivers, lakes, and water holes; different age groups may utilize different habitat types.

During the rainy season, when its home waterway floods, a Nile crocodile will migrate, often over a long distance, to a "drier waterhole," returning to its original home when the water level falls.

Diet

The Nile crocodile is an ambush predator, lurking just below the surafce while waiting for a victim to come to the water for a drink. The strike is usually very quick, with the intended prey having virtually no time to react before being grabbed and drug underwater, where it will be held until it drowns. Because crocodiles cannot chew, the carcass will be kept under water, usually wedged under logs or rocks, until it is soft enough to be eaten. The entire animal will be eaten, including hooves, antlers, etc.

Mammals make up the majority of the crocodile's diet, but reptiles (including other crocodiles), birds, fish, and carrion are also taken. Juveniles usually feed on insects, small fish, amphibians, and crustaceans. Prey size increases as the crocodile's size increases, and large adults are capable of taking prey up to the size of antelope, buffalo, zebras, and wildebeest.

Reproduction

Mating usually occurs during the dry season.

Up to 70 eggs are laid in hole dug by the mother into a sandy bank near water. The mother will stay close to the nest throughout the 3-month incubation period, but will leave it unguarded in order to feed. As soon as the first sounds of hatching are heard, she will uncover the nest, crack open eggs if necessary, and carry each hatchling to the water in her mouth. The young will stay as a group near the mother for several weeks, dispersing as they reach a "self-sufficient" size.

As with other crocodilians, the sex of the young is determined by the incubation temperature, with females produced under 85º F and males over 85º.

Sexual maturity is reached at 6-7 years. Nile crocodiles can live up to 100 years.

Other Information

Fully-grown adult Nile crocodiles are primarily solitary and territorial, but juveniles and smaller adults may form into small groups in order to avoid being preyed on by larger crocodiles.

In Africa, the Nile crocodile accounts for more human deaths per year than any other carnivore.

Conservation Status

Nile crocodiles are still fairly numerous throughout their entire range, but some local populations are threatened with habitat loss and/or over-hunting.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Reptilia
order Crocodilia
family Crocodylidae
genus and species Crocodilia niloticus

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This page was last updated on June 20, 2018.