Nile Crocodile

Nile Crocodile

Reptiles

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 lb.)
DIET: Up to 70% of the adult diet is fish. Other prey items may include zebras, hippos, porcupines, pangolins, and migrating widebeest.
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 Males are mature at roughly 3 m (10 ft.); approximately 10 years of age
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.