Why Are There Alligators On The Banks Of The Nile?

This is yet another of those questions that comes up as I work through the backlog of questions I have from my son – a question that has no context. I’m pretty sure that it came up because he loves watching nature programs, but I can’t remember the original cause of the question. Still, it should be a good one. So, rather than speculate on where it came from, let’s jump on in and try to answer it.

Are there alligators on the banks of the Nile?

The simple answer to this question is “no”. Crocodiles live in the Nile, not alligators.

What’s the difference?

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Alligators are part of the Alligatoridae family, which includes the subfamilies Alligatorinae and Caimaninae. Alligatorinae includes the genus Alligator and the two currently living species of that genus:

  • A. mississippiensis, the American alligator, which lives in the southeastern United States.
  • A. sinensis, the Chinese alligator, which lives in the lower Yangtze River.

Alligatoridae is just one family in the order Crocodilia, along with Crocodylidae and Gavialidae. “True” crocodiles, which includes the Nile Crocodile (Crocodylus niloticus) belong to Crocodylidae.

So that’s the difference in nomenclature. There are morphological differences as well, as described on livescience.com

  • Snout shape: Alligators have wider, U-shaped snouts, while crocodile front ends are more pointed and V-shaped.
  • Toothy grin: When their snouts are shut, crocodiles look like they’re flashing a toothy grin, as the fourth tooth on each side of the lower jaw sticks up over the upper lip. For alligators, the upper jaw is wider than the lower one, so when they close their mouths, all their teeth are hidden.
  • Home base: Crocodiles tend to live in saltwater habitats, while alligators hang out in freshwater marshes and lakes.

Although alligators are primarily freshwater animals, they can tolerate salt water. In 2010, an alligator was spotted some 20 miles off the cost of Georgia swimming with whales. The article notes that while it is not unusual to find saltwater fish in the stomachs of alligators (or saltwater stingray barbs in their cheeks), the distance this one was spotted at was unusual. “It is likely this gator swam into the Altamaha after a day of sunning and was swept out to sea by unseasonably cold water after recent heavy rains. Too chilled to fight the waters that carried it, the alligator ended up farther out at sea than what is considered normal.”

Nile Crocodiles

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Crocodylus niloticus, the Nile Crocodile, is not actually restricted to the Nile River. They can be found pretty much everywhere in Africa that isn’t desert, with a habitat that covers lakes, rivers, freshwater swamps, and brackish water. In optimal conditions they can reach up to 5 meters in length, although they can run between 2 – 4 meters in less favorable conditions (cool or dry or both) – there are also unconfirmed reports of animals up to 7 meters long.

This should probably go without saying, but the Nile crocodile is a wild animal and potentially dangerous. And you, dear reader, look like a prey animal to them. Still, there aren’t that many reported crocodile attacks on humans: from January 2008 to October 2013, 466 Nile crocodile attacks on humans were reported, approximately 325 of which were fatal. That’s about 8 attacks per month, 5.6 of which were fatal.

That sounds intimidating, right? But it’s hardly a leading cause of death. According to the CDC, Heart disease kills 1,674 a month and suicide kills 113 people per day. In the United States, at least. In Sub-Saharan Africa (to compare apples to apples), AIDS alone kills 3,035 people per day and diarrhea kills 1,764 per day.  So really, crocodiles are among the least of your worries if you live there.

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