Scientific Classification

Common Name

Nile crocodile

Kingdom

Animalia

Phylum

Chordata

Class

Reptilia

Order

Crocodylia

Family

Crocodylidae

Genus Species

Crocodylus (crocodile) niloticus (belonging to the Nile River)

Fast Facts

Description

Large, lizard-shaped reptile with four short legs and a long muscular tail. The hide is rough and scaled. Juvenile Nile crocodiles are dark olive to brown with darker crossbands on tail and body. Adults are uniformly dark with darker crossbands on tail.

Size

Averaging approximately 5 m (16 ft.) with maximum size of roughly 6 m (20 ft.)

Weight

Adults of both sexes may easily exceed 225 kg (500 lbs.)

Diet

Up to 70% of the adult diet is fish. Other prey items may include zebras, hippos, porcupines, pangolins, and migrating wildebeest.

Incubation

Approximately 3 months
Females nest in November and December on sandy shorelines, dry stream beds, or riverbanks.

Clutch Size: A female can lay 25-100 eggs, which she covers with sand, then guards until they hatch.

Sexual Maturity

Relates to size

Male: Relates to size

Female: Females are mature at roughly 2 m (6.5 ft.); approximately 10 years of age

Life Span

Average approximately 45 years in the wild, may live up to 80 years in captivity

Range

Found throughout tropical and southern Africa and Madagascar

Habitat

Rivers, freshwater marshes, estuaries, and mangrove swamps

Population

Global: No data

Status 

IUCN: No data
CITES: No data
USFWS: Endangered

Fun Facts

1. A crocodile's ectothermic metabolism is extremely efficient. A large crocodile, which may weigh more than 900 kg (2000 lb.), can survive for long periods of time between meals!
2. If baby crocodiles are in danger, the adult female may pick them up and flip them into her mouth or gular (throat) pouch for protection.
3. When fish are migrating, crocs may hunt cooperatively by forming a semi-circle across the river and herding the fish. They then eat the fish that are closest to them.
4. When young crocodiles are hatching, either parent may help them out of the egg by rolling it between their tongue and palate. This cracks the shell allowing for an easier escape.
   
    

Ecology and Conservation

Nile crocodiles are ecologically important as predators. They help the environment by keeping barbel catfish, which are predators themselves, in check. Barbels eat other fishes which are the diet of more than 40 species of birds. If birds leave an area because there are no edible fish, the amount of bird droppings, which provides nutrients for the fish, declines, and the food chain is disrupted. Unfortunately, the Nile crocodiles' population suffers from pollution, hunting, and entanglement in gill nets.

Bibliography

CSG Newsletter, Vol. 2 (1), Jan-Mar 1992. IUCN World Conservation Union Species Survival Plan Commission.

Halliday, T. and K. Adler, eds. Encyclopedia of Reptiles and Amphibians. New York: Facts on File, Inc., 1987.

Ross, C., ed. Crocodiles and Alligators. New York: Facts on File, Inc., 1989.

Steele, R. Crocodiles. London: Cristopher Helm Ltd., 1989.

Vissen, J. and T. Pooley. The Tony Pooley Guide to the Nile Crocodile and other African Crocodiles. 1982.