An animal so often feared and such a master of concealment, and so incredibly adapted to its environment in so many ways…
Leaving for game drive invariably takes you past one of the water holes close to camp, often even more than one. It is here where I frequently see something that I will often stop and show to guests; the tracks of where crocodiles have moved at night and left their own waterhole and walked towards the river or vice versa.
It’s almost impossible to miss the tracks in the road as you can see where these prehistoric creatures’ unmistakable feet have landed while dragging their big tail through the substrate.
We were lucky enough to see this crocodile moving from one water source to another in the early hours of the morning. It stopped moving as we approached. It is characteristic drag marks left behind from crocodiles like this that have got our attention in the past.
These scrapes in the sand often spark a lot of questions. When do you think it moved through? and how do they move from one water source to another? are two common ones. The majority of the time we only see these prehistoric beings as they lay motionless basking of the banks of the river or waterholes, or we see just the top of their head as they are slowly gliding effortlessly through the water.
When we see them basking of the banks they are obtaining heat from the sun which is then converted into energy, unlike humans and other mammals who need food to convert energy, crocodiles are poikilotherms and derive their body temperature from the ambient temperature of their surroundings. But that’s a whole story in its own.
Here you can see a crocodile basking on the bank. By opening its mouth it is able to thermoregulate further through hundreds of small blood capillaries which are situated in the mouth.
Basking crocodile, it is said that hatchlings grow 30cm a year and at birth are around 30cm, so this one would probably be around 1 year old. But this baby crocodile used the belly crawl method to slide away from any danger.
What fascinates me the most is how these reptiles are able to travel large distances in search of water.
I have personally seen crocodile tracks and the distinctive tail mark a few kilometres (!) away from any water point.
Which leads to me my next question: how do they walk and what allows them to walk such a great distance?
I’m sure a lot of you reading this have seen a crocodile or alligator dash into the water from the banks of a water source, whether it be here at Londolozi or on TV. There are two different locomotive methods they use; the first is called a “belly crawl”, which is what we see most often and is where most of their body is touching the substrate beneath them as they move into the water. This can be done at a rather slow pace and they pretty much push their body on the sand or grass and slide into the water, or if threatened at some serious speed as seen in the picture below.
This crocodile had been going through courtship and was being chased by a male crocodile. They will use the “belly crawl” technique to get away when the water is in close proximity where they can then use their powerful tail to propel themselves away from any threat. The belly crawl locomotion is a fast and easy method for them.
The second; the “high walk”. It is so called because of how the crocodile is able to lift its entire body trunk on those short legs and at least the anterior half of its tail clear of the ground when it walks. It is usually a relatively slow gait when they are in the “high walk” posture; they often don’t exceed 2 to 3 kph. However, the crocodile can speed the gait up when threatened and reach speeds in excess of 5kph. When they do this they will exert a lot more energy.
This crocodile was crossing the cause way where we cross the river into the north and one can clearly see how a crocodile will drag its tail on the ground behind. At first glance one could be mistaken this drag in the sand for another type of drag mark we all so excitedly look for on game drive but this drag mark has a story of its own.
The high walk is a product of a unique body adaption in the form of bony ligaments and scales. When a crocodile stands up there are interlocking bony plates on the dorsal scales and legs formed by complex ligaments which lock into place, allowing the crocodile to raise its entire body. This arrangement creates a semirigid “I-beam” structure which encloses the back muscles. This then becomes rigid but is flexible enough to allow an efficient transfer of energy from the tail of the crocodile to the erect body posture while walking.
This crocodile was seen walking past the northern end of the airstrip in-between waterholes and is using the “high walk” to get from one place to another. Its whole body has raised off the ground which allows the crocodile much easier movement when walking further distances. They are also at a much higher risk of being attacked by the likes of lions as they are not in their natural territory while on land.
A close up view of how a the crocodile is able to raise its body up off the ground.
Crocodiles have literally had millions of years to evolve to these types of locomotion.
I wonder how long ago this evolution specifically began or was it something they could do from the beginning?
Crocodiles to me are one of the most advanced creatures we are able to view when out on safari. They have stood the test of time, essentially being one of the most prehistoric creature which roams our planet today…
Interesting blog Guy.
Guy, I loved crocodile🤗
Great article Guy and some great photos too.
Aside from the privilege of having visited Londolozi on a number of occasions, we are regular visitors to the Mabula (Mokaikai) Game Reserve, where we have got a share in a lodge. We have a number of monster crocodiles here and linked to the rainy season when secondary dams replenish, individual crocodiles traverse the best part of 7 to 10km between dams. Their adaption to the environment is incredible and they have a sixth sense to know when conditions are good to move and I suspect also, to know that hunting in the smaller dams will be easier. One year after such a move, one particular individual disposed of an adult buffalo and also an adult zebra (managed to get a photo of the tail-end of the zebra incident, when all that was left, was the head and neck, which this croc ‘guarded’ by clasping it sideways in his mouth until such time as his appetite developed to allow it the ingest this as well.
Congratulations to you and to your colleagues on your excellent and always enjoyed posts !
Very Interesting! We all knew the “Moon Walk”, but who knew there was a High Walk!!!
We have frequently seen crocodiles basking or doing the belly crawl. Last visit was the first opportunity to observe the high walk across the causeway–good timing as with many sightings.
Guy, thanks for the great education on crocodiles! The images from the team are great. We love the one you got of the crocodiles coming right at you! Well done!
Good foto’s to see how they do the “high walk”, very unique position. Different from the”belly crawl” which most of us have seen the crocodiles do. Very intriguing to hear that they walk from one water hole to the next. Thanks Guy for a good story on the crocs.
That was very interesting! Thanks for giving us more detail on how the crocodiles transport themselves when out of the water!
Crocs still make me shiver with dread…….that malevolence (real or imagined)!
Beautiful images of crocs. Although many people don’t want to have anything to do with crocodiles I think they are actually very interesting creatures. No, for us humans they are not very lovable, but they have a very interesting way of life and the females are very good mothers.
Fabulous, informative blog today Guy. I remember sitting on the causeway watching a grey heron who had just caught a fish, knocking it against the rock to kill and spear it, all the while in the midst of sun basking crocodiles – a magical moment.
I enjoy these diversions from the “ normal “ game viewing blogs, and as much as I live for big cat viewings or elephants, I appreciate seeing and learning more about the non- big five.
Very interesting story and great pictures, though I must own that I am not really fond of crocodiles.
i am sorry, but I find them terrifying !! Victoria
Fascinating Guy..and some awesome shots too ! 👌🏻❤️
What is your response to “how do they move from one water source to another?”? You don’t mention their highly developed, very camouflaged, delta wings do you?
Regards when they started to be ambulatory on land I think that mudskippers and Pecan beaching to catch seals show that when Nature dictates “adapt or die”, Nature provides the means. Snakes have vestiges of fore-limbs.
Interesting blog, Guy! Nile crocodiles are fascinating creatures- kinda creepy but fascinating!!
Great post on the crocs Guy! They’ve totally fascinated me since childhood, watching them on nature shows menace their way around! I love how you ended the post with their incredible resilience and evolution from prehistoric times.
Thanks, a wonderful blog- learned something new. Always appreciated
Field Guide Guy, I would like to know how much Kg’s can a crocodile eat in a day?
I learned a lot from that post! Crocodiles are so fascinating and ancient. It’s a marvel they are still around for us to see them ! I can’t imagine a Lion (or anything ) trying to eat one – it looks really tough and full of scales to eat.