Crocodylus niloticus
One of Africa’s most dangerous animals, the Nile Crocodile is also by far the largest and one of the most widespread reptiles found on the continent. Adults measure on average around 3.5m long , but the largest accurately recorded specimen (from Tanzania) had a length of 6.45m and weighed 1090kg!
Nile Crocodiles inhabit rivers, marshes, lakes, lagoons and estuaries, and even venture out to sea at times. From hatching crocodiles are entirely carnivorous, feeding at first on small fish, insects, crustaceans and frogs. Fish also make up about ¾ of the diet of adult Nile Crocodiles, though they are capable of drowning animals up to the size of an adult buffalo when the opportunity presents itself! Such a large meal can sustain the crocodile for many weeks. When a meal is too large to swallow in one gulp, Nile Crocodiles will take a large bite and then spin their bodies in the water to tear a mouthful of flesh from the carcass. We’ve also seen Nile Crocodiles using their bodies and tails to trap schools of fish against the bank and pick off their hapless prey one at a time.
Often living in close proximity to sizable human populations, it is no surprise that Nile Crocodiles are responsible for hundreds of human deaths annually, especially when people are directly reliant on waters inhabited by crocodiles for their daily needs (fetching drinking water, fishing, washing clothes, bathing, etc).
At times, Nile Crocodiles can congregate in huge numbers, especially when water resources dwindle during the dry season or at a favourite nesting area. They are surprisingly fast on land, and capable of running at up to 17km/h! By day they like to bask in the sun on a rock or sandbank with their mouths wide open when they start to overheat, preferring to stay in the water at night. They hunt mostly at dawn and dusk, approaching prey on land with only their nose and eyes breaking the surface of the water.
Adult male Nile Crocodiles are territorial, and often get involved in deadly battles with other males. In South Africa the mating season stretches through winter, with the females then moving to a favourite, suitably sunny spot high enough above the floodline, to dig their nest – a hole in the sand between 20 and 45cm deep. Here she lays up to a 100 eggs, which she then covers again with sand. She diligently guards the nest for the next three months until the eggs hatch. The hatchlings call out to their mother, who digs them out and moves them, very carefully, to the water in her mouth. She looks after them for another 2 to 6 months in a nursery area, which is usually a densely vegetated stretch of water (they feed themselves from hatching). The eggs and hatchlings are a delicacy for a wide range of predators both on land and in the water, and despite the mother’s best efforts only about 2% of eggs laid reach maturity. The temperature at which the eggs are incubated determines the sex of the babies – lower temperatures produce females. Young crocodiles spend much of their time out of the water catching insect prey. It is estimated that Nile Crocodiles can live to an age of 100 years in the wild.
The IUCN lists the Nile Crocodile as “lower risk / least concern“, and while the species is threatened by habitat loss, environmental poisoning and poaching their numbers across their distribution range are estimated at between 250,000 and 500,000. It is found from the upper reaches of the Nile in Egypt, and most of West Africa south of the Sahara, southwards through Equatorial and East Africa to Angola in the West and to South Africa’s east-flowing rivers from the Tugela nortwards. They are also found on Madagascar and farmed for their meat and leather in several countries. In South Africa wild Nile Crocodile populations are considered to be vulnerable. The country’s largest wild populations are to be seen in the iSimangaliso Wetland Park and Kruger National Park, while the Crocodile Centre on the outskirts of the town of Saint Lucia in Kwazulu-Natal is a must visit for anyone interested in this species as well as the two other African species of crocodiles (few authorities have as yet recognised the West African Crocodile (C. suchus) as a seperate species).
Why do crocodiles only occupy rivers that flow West to East? I have been looking everywhere on the internet and haven’t found a thing
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I wonder whether you might be speaking about the crocodiles in South Africa specifically, as they occur in many westward flowing rivers further north in Africa? In South Africa there’s two main reasons for them only occurring (now) in the rivers from the Tugela nothwards, all of which flow into the Indian Ocean on our east coast. The first reason would be that some rivers are simply too cold – think of those flowing short distances from the mountains to the sea in the Western Cape, often carrying melted snow. The second reason is that humans eradicated them from their natural haunts, as in the case of the Orange and Vaal River systems.
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You have taken such wonderful photographs of this hideous, prehistoric, lethal throwback, which must never be lost to us now, even though it is a killer. Thank you for sharing this wonderfully informative post…
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They certainly have a very important part to play in the ecosystem!
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Ek bly maar ver uit sy pad
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Dis by verre die veiligste!
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What a superb collection of crocodile photos. I always find crocs scary but rather mesmerising!
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Thanks a lot, Jude! They’re awesome creatures, especially when you see them in action!
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🐊🐊🐊🐊🐊🐊😀
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This is one bad-boy I would not want to miss with!!
It’s really interesting that temperature at incubation affect the sex of the hatchlings. Does it stand to reason that from year to year, there would be predominantly male or females being hatched depending on the weather … or that in a single laying of eggs, they would all be of the same gender?
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It mostly depends on the spot (sun vs shade), and the depth at which they are laid, Joanne, and thus how warm the nest gets inside. In the same clutch there could be babies from both sexes, the deeper eggs developing into females and the top ones males, for instance.
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Ahhh – thanks for the clarification. I can visualize that 🙂
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I’d love to see one…from a distance…a very great distance! Definitely a zoom lens creature!
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They’re very scary alright!
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So much more to learn. Wow!
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Glad to know you found our post so informative, Ruth!
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De Wet, ek en Bertus het nou hier behoorlik ‘aan jou lippe gehang’. Het jou stuk dadelik aan my kleinseun gestuur, hy gaan dit net so waardeer.
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Baie dankie vir die gawe kommentaar!
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Wow! Impressive pictures you have taken! 🙂 I have seen many tv shows on Animal channels about the Nile crocodile, they are very aggressive and the second dangerous and biggest after the saltwater crocodile.
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Thanks, John. Indeed, Nile Crocodiles are extremely dangerous!
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Weereens uitstekende foto’s en inligting, Dries! Krokodille is vir my een van die grusaamste wesens.
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Hulle is heeltemal angswekkend genoeg om te sorg dat ek nie enige waters waar hulle dalk kan voorkom sal binnegaan nie!
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As dit nat is,is daar ‘n krokodil…dis my leuse😳
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Dis nou n leuse waarmee mens jouself aan die lewe kan hou!
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Yikes!
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😀
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Awesome creatures!
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Absolutely!
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Scary creatures indeed. I certainly didn’t know they could get to the size of that monster you mention. Depressing that although they are ‘lower risk’ South Africa is so backward that they are regarded as vulnerable here. More mismanagement?
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They were mostly eradicated from areas outside of our major conservation estates decades ago, and hopefully will make a comeback. They certainly thrive with adequate protection in places like Kruger and iSimangaliso.
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