Genus & Species: Crocodylus niloticus
The Nile crocodile is found along the Nile River Valley in Egypt and Sudan and distributed throughout most of sub-Saharan Africa and Madagascar.
Nile crocodiles occupy a variety of aquatic habitats including large freshwater lakes, rivers, freshwater swamps, coastal estuaries, and mangrove swamps. In Gorongosa, Lake Urema and its network of rivers are home to a large crocodile population.
Nile crocodiles can be active at any time but are frequently active in early evening. They behaviorally thermoregulate by moving into water or shade when they get too hot and bask in the sun when they are too cool.
Lifespan is not well documented, but 70 years or more is likely.
Crocodylus niloticus means “pebble worm of the Nile” referring to the long, bumpy appearance of a crocodile. Juvenile Nile crocodiles tend to be darker green to dark olive-brown in color, with blackish cross-banding on the body and tail. As they age, the banding fades. As adults, Nile crocodiles are a grey-olive color with a yellow belly. Their build is adapted for life in the water, having a streamlined body with a long, powerful tail, webbed hind feet and a long, narrow jaw. The eyes, ears, and nostrils are located on the top of the head so that they can submerge themselves under water, but still have sensing acuity when hunting. Crocodiles do not have lips to keep water out of their mouth, but rather a palatal valve at the back of their throat to prevent water from being swallowed. Nile crocodiles also have integumentary sense organs which appear as small pits all over their body. Organs located around the head help detect prey, while those located in other areas of the body may help detect changes in pressure or salinity.
- Ecology, Adaptations, Etc:
Often mistakenly thought to be anti-social, crocodiles must co-exist, often in large aggregations. For example, large groups of crocodiles will congregate in areas of high fish density and create a large semi-circle, blocking the fish from traveling further downstream. The larger and more dominant males will have access to the better fishing spots, but all crocodiles partake in the effort to eat. Large groups of crocodiles are often found basking together.