African Crocodile – Crocodylus niloticus
Crocodiles are tropical reptiles. They are thick skinned and lizard-like in shape. Adult crocodiles grow to between 2.5 m and 4.2 m. The African crocodile is recognisable by its narrow snout. It has three or four rows of protective scales on the back of its neck, which merge with the scales on its back (other members of the Crocodylus genus have only two rows of scales). The fourth tooth of the African crocodile’s lower jaw sits outside the crocodile’s lips even when its mouth is closed.
Crocodiles are found primarily in freshwater rivers that have dense vegetation cover. They can also be found in large lakes. Crocodiles are most at home in the water, but are able to travel on land.
Crocodiles are carnivores. They use their sharp teeth for catching and holding their prey. Their diet is thought to consist primarily of fish and small aquatic invertebrates. Young crocodiles feed on worms and insects. While adults eat frogs, tadpoles, and opportunistically on larger prey if it becomes available including humans.
The African crocodile is generally not found in groups, except during the onset of the breeding season. At the onset of the rainy season female crocodiles construct nests out of plant matter on the banks of rivers, although breeding occurs year-round. Female African crocodiles lay between 13 to 27 eggs about a week after they have finished building their nests.
The female remains close to the nest for the 110 day incubation period, but does not defend it quite as ferociously as many other species of crocodile. Once the eggs begin to hatch, and the hatchlings emit their characteristic chirping, the female breaks open the nest to assist in the hatching process. Predators of the hatchlings include the soft-shelled turtle, but most young African crocodiles survive to maturity.
Although the African crocodile does not have many natural predators, the crocodile population is declining due to over-hunting by man. Areas where the crocodile population is severely depleted, if not entirely wiped out include Angola, Chad, The Gambia, Guinea-Bissau, Nigeria, Senegal, Zambia, Congo and Togo. The largest population stronghold exists in Gabon. Habitat destruction has also contributed to the population depletion.
Poorly-enforced protection exists for the remaining populations, although some countries allow regulated hunting. Before significant action can be taken in conserving the crocodile population, studies on ecology, population dynamics and status need to be undertaken – which is difficult in areas subject to political instability.