Green anoles are excellent climbers.
You probably already know this seeing how quickly they scale up walls, plants, and fences.
(Sometimes, even ceilings!)
They’ve evolved to quickly climb up into their arboreal world using a few traits their bodies have developed.
In this article, we’ll go over a few of the phenotypes that make them climb so well.
Table of Contents
Ventral scales
If your anole is tamed, gently try brushing up on it with your finger. Use your index finger and gently rub it on the ventral (bottom) side of the lizard.
If you rub upwards from the head to the tail, you’ll notice that it’s very smooth and your finger slides easily.
If you rub downwards from the tail to the head, you’ll easily feel that it’s rough and hard to move your fingertip.
This is because the scales are positioned in one direction. The lizard moves forward easily, but can’t move backward. It adds extra “grip” by creating friction against surfaces so the lizard can climb up surfaces without slipping back down. This is also what helps them traverse vertical or steep surfaces.
Pretty cool, huh?
Toes
Their toes are a work of science! Look at this photograph. It’s a macro shot of the toes:
See how they have hundreds of those little “flaps” of skin going down each toe. The flaps have even smaller, microscopic fibers called setae. These are like tiny hairs that stick out from the toe.
They each exhibit a small reaction to the surfaces they climb on, known as Van der Waals force. It’s a fascinating thing to discuss, but it’s a rabbit hole. In summary, they act like suction cups which allow them to “stick” to surfaces to climb.
This is why anoles are so good at climbing trees, walls, fences, or other rough surfaces. It even works on smooth surfaces- pretty much anything but Teflon. Wet or powdery surfaces also may deter them from climbing. The hair is split into tiny suction pads called spatulae.
When they climb, they uncurl their toes with each little step they take. Each time, the tiny hair will roll out to the surface and then stick to it.
Isn’t that cool? The reverse then takes place when they take their feet off the surface. These guys can do it quickly which gives them amazing speed.
Feet pads
The next time you handle your anole, take a look at the bottom of its feet- for the seat. These are small hairs that you can feel when you brush your fingertip on the bottoms of their feet. It feels “grippy” with a lot of friction.
Each setae hair has an even smaller pad on it (so it’s like a foot pad on their foot pad) called spatulae. Each spatula is about 1/10 of a human hair in diameter. So they’re extremely tiny, but there are so many of them that it increases the surface area of objects they climb on.
This allows the Van der Waals forces to be magnificent. Each spatulae combines together for an aggregate force of huge proportions. According to this source, the number of setae that cover the size of a single dime (1 million setae) can lift upwards of 45 pounds. How’s that for teamwork?
Green anoles will constantly rotate their feet to attach and detach their feet from surfaces. They slide their feet into position to activate the nanostructure of setae in order to suction cup themselves onto vertical surfaces.
They can do this up to 15 times per second, which is fast. They don’t even utilize all their seats when they don’t need to. It really depends on what they’re climbing on. If the surface is waxy or slippery, they utilize more of their hairs. If it’s smooth or flat, they use less. That’s efficient.
Body structure
The physical structure of a lizard is a long, narrow body with minimal surface area laterally.
They’re shaped like a submarine because it provides little obstruction to the left and right so they can dart through the arborage going forward. They have plenty of vertical surface area, being that their entire body is like a giant suction cup which makes vertical distance scaling simple.
It keeps them from falling when they climb. From head to tail (vent to nose), these reptiles are optimized for vertical climbing with minimal slippage. There’s friction when going backward, but not forwards. That’s why they don’t slip back when climbing up.
This is why your green anole is such a good climber!
In summary, green anoles are excellent climbers because they maximize the surface area on their body through the aggregate interaction of millions of tiny hairs.
With each seat exuding an interaction with the surface they climb on through the process of Van der Waals forces it gives them a “suction cup” effect so they can climb like crazy.