Nile Crocodile

Nile Crocodile - fearsome reputation, loving parents

Rivalled by sharks, crocodiles are greatly feared yet held in awe by people - even those who have very little chance of coming into contact with them. The plethora of video films featuring the often brutal killing habits of these aquatic predators are clear testimony of man's infatuation with drama and danger. All too often, these films - many compiled on small budgets - tend towards melodrama and do little to provide a balanced picture of these powerful carnivores.

Like other predators at the tops of food pyramids, crocodiles perform a vital function in ecosystems. Although large predators rarely regulate numbers of their prey (this is controlled largely by the availability of their own food) they do regulate the fitness of the animals that they habitually prey upon. Crocodiles, however, are highly opportunistic and feed to a very large extent upon the dead or disabled. When crocodile numbers in Botswana's Okavango Delta were reduced by unsustainable ‘harvesting' in 1970s and 1980s, the population of catfish (one of their favourite prey items) increased dramatically and repercussions were felt along the food chain and these fish impacted on other species. Clearly, the crocodiles were playing an important regulatory role, to the benefit of the ecosystem as a whole.

Loving Mothers

Less known than its hunting habits, is the crocodile's tender parental care - astonishing for a primeval reptile whose bodily form has remained unchanged for the past 100 million years. Female crocodiles bury their clutch of 50 or so white eggs in a shallow burrow close to water, and then rest nearby throughout the 90 day incubation period. Once the eggs hatch and the tiny, finger-sized young emerge, they begin yelping and the diligent mother carefully takes each one in her mouth. Even unhatched eggs may be picked up and gently cracked to release the young. Packed into their mother's gular pouch, the hatchlings are safe until she releases them at the water edge.

Mortality and Lifespan

The Nile Monitor is a serious threat to crocodiles as this large lizard readily digs up the eggs from their sandy nest. When the young crocs reach the water, they are vulnerable to a host of predators including large predatory fish, fish eagles and herons. Crocodiles which see out their first two or three years become virtually immune to predation and may live to a great age. The ‘monsters' which lie in wait for wildebeest and zebra in East Africa exceed three metres in length and are well over 50 years of age. Man is, of course, the biggest threat to crocodiles and intense hunting for valuable skins reduced or eliminated populations in many parts of the continent. Today, sustainable crocodile farms provide ably for the trade in skins (and crocodile meat is a delicacy in some countries) and also help to re-stock areas where populations have been eliminated or are low, with youngsters.

CC Africa's Crocodile Hotspots

Huge Nile Crocodiles live in the Mara, Sand and Grumeti rivers which bisect the Serengeti-Mara ecosystem in Tanzania and Kenya. These impressive creatures are most readily seen by guests staying at Grumeti and Kichwa Tembo. Heavy hunting up until the 1980s in the Okavango Delta and the Zambezi River, targeted the largest individuals and the numbers of large, old crocodiles here is comparatively low. Nevertheless, Matetsi, Sandibe and Nxabega provide the opportunity to get close to crocodiles on boats. Crocodiles also occur at Ngala, Londolozi and Phinda, where some impressive individuals are resident.

Posted: Other by CC Africa, Date: 21 November 2006