Crossing over the Sand River at the causeway always provides something interesting to marvel at. From the large pod of hippos in the southern pools to giant kingfishers that perch so close to the road that you can have an up close and personal view of every tiny little detail from just a few meters away, as well as the many other species of birds from Reed Cormorants, Hamerkops, Three-banded Plovers, Pied Kingfishers, to African Fish Eagles to just name a few. One often finds themselves torn between which way to look. The one thing that always catches our attention is the crocodiles that either lie on the banks basking in the sun or have placed themselves in the water currents in the hopes of catching any fish or prey being washed over.
A crocodile waits patiently for fish to be swept into its open mouth.
After admiring these ancient-looking animals, the question is often asked,
“What is the difference between crocodiles and alligators”?
The Simplest explanation is, that we don’t get alligators here in South Africa we only get crocodiles, alligators are normally found in North America. Be that as it may, I thought I would still share a few of the differences between these two enormously successful animals.
Eye to eye at sunset with one of Africa’s apex predators; the Nile Crocodile.
Firstly, crocodiles belong to the Crocodylidae family (which includes 14 species throughout, Asia, Africa, Australia and the Americas), and alligators belong to the Alligatoridae family (only found in the Americas and Asia), this family also includes caimans, but I am going to focus on the alligator.
The top image is an Alligator with a U-shaped snout, and the bottom image is a Crocodile with a V-shaped snout.
Image: everythingreptiles.com
The shape of their snout is one of the most noticeable differences. Often crocodiles will wait patiently right at the edge of the downstream side of the causeway, with their jaws open in the hopes that unsuspecting fish will be swept into their mouths. Here we can see clearly, the pointier snout of the crocodile that is V-shaped. Whereas an alligator has a broader snout in the shape of a U.
There was a perfect shaft of light coming in from in front of this crocodile to illuminate the inside of its yellow mouth. It was too unique to pass up, and the slow shutter speed added to the mystical feel of the scene.
It’s always enjoyable to spend time at the causeway and experiment with a slow shutter speed on your camera. The crocodiles that sit and wait for fish or frogs to get washed over are great subjects to focus on but make sure you have a bean bag or tripod to keep your camera still.
If you manage to get a good glimpse of a crocodile’s teeth you will notice that some of their bottom teeth are exposed when their jaw is shut, most noticeably the 4th tooth from the front. This differs from the alligator as typically only their top teeth are shown. A crocodile has a stronger bite force measuring about 3700 psi (pound per square inch), and alligators’ strength is 2500 psi.
A close-up of a crocodile’s teeth shows the exposed 4th tooth.
Adult crocodiles are dark olive-green or brown in colour with darker markings on the back, side and tails. Alligators are slate grey with yellow to the whiteish underside.
Pictured here is a young alligator with the yellow-white underneath its jaw and the smaller teeth mostly visible on the top jaw.
On average crocodiles are bigger than alligators with adults reaching between 3.5 – 5 meters in length, whereas alligators’ average length is between 2.5 – 4.5 meters.
A crocodile crossing the causeway perfectly shows the olive-green skin colour.
In order to detect prey in murky waters where visibility is limited or impossible, both crocodiles and alligators use special sensory organs on their skin that detect small disruptions in the water, known as dome pressure receptors. But an interesting difference is that they are scattered all over the body of the crocodile and are just visible as tiny black spots near the jaw of an alligator.
So next time you are here at Londolozi and see a crocodile, or even if you happen to come across an alligator somewhere else in the world, take a bit of time to see if you can see the differentiating features.
Very interesting article illustrated with beautiful images. Have learned a lot!
Having lived in Florida, USA for many years I became very familiar with Alligators and the differences between gators and crocs. Your analysis is very good. Thanks for reminding me. I do like your photos of both creatures, well done thanks Tayla.
Wel explained thanks Tayla. Some stunning foto’s were taken , the crocodile walking is an impressive foto. But they scare the life out of me.
Thanks Twyla, for the interesting article.
I must say that of all the bigger animals, crocodiles are the ones I really am frightened of and which I don’t like though I think they are fascinating. Sometimes even quite funny, like the ones that you have at Londolozi at the causeway. With their ever open mouths, ready to catch any prey that happens to come their way.
Thanks Tayla for writing a definitive article on the differences between alligators and crocodiles. It’s easy to mis-identify when you’ve not spent time viewing either one. Traveling to Africa, one can be assured to see only crocodiles.
I love spending time on the causeway where I captured my first shots of a giant Kingfisher and Hammerkop in addition to the “resident” croc, lurking at the edge in hopes of something good to fall into his/her mouth.
Living in Florida, we experience alligators regularly. Your contrasts with crocodiles is informative. I have commented previously that stopping at the causeway has been one of my favorite places in Londolozi.
The image of “perfect shaft of light coming in from in front of this crocodile to illuminate the inside of its yellow mouth.” does not identify the photographer.
Thanks for this great article.