Monitors: The mind of a lizard genius?

Most of the time when we think of intelligence we consider animals like mammals or birds. Don’t get me wrong, dogs and parrots are smart but is there another group of animals that their shrewdness is overlooked? Some species of reptile are highly intelligent and capable of solving complex issues. One of the most cunning groups of reptiles is the monitor lizards. These animals are capable of feats that once were thought to be doable only by mammals and birds.

Lizards have to have a strong ability to change with their environments and a huge part of that is having the ability to learn.  They must be able to figure out complex issues in the wild so that they can survive. Lizards need to remember a map of their territory in order to know where and when to find their food. One experiment with Anoles proved that they will, in fact, distinguish between two different colored spheres to find food ¹. This indicated that Anole's have an innate ability to learn where a food source is located. Another study was conducted with Tuatara lizards and lights ². The lizards were subjected to a steady light and a blinking light. One of the lights would reward them with food. The other one would not. In just a few trials the lizards picked up on the light that provided food. I’ve seen something similar to this with a Savannah Monitor named Tigger. 

 

Tigger associated a dark cylinder with food. In the hollow tube were crickets and when the tube entered his cage, food would fall from the tube. After a little while of feeding him this way, he would come out of his hide when the tube would enter the cage. Tigger would attack the tube and chase after it to get his food. This form of learning is known as classical conditioning. Tigger associated his hunger with the dark, hollow, cylindrical tube that gave him crickets. This particular occasion is what ignited my interest in the learning abilities of monitor lizards.

In one study, two Rough Neck Monitors and a Komodo Dragon were evaluated on reversal learning abilities ². The monitors were given a choice between a black or white stimulus. One would have a food reward and the other would not. After a set amount of time the researcher would change the color that would give a food reward. It didn’t take long at all for the monitors to start picking the other color that provided food.

Monitors also have the ability to learn from other monitors². A good example of this is if a monitor see’s another monitor get attack by an eagle because it was running across an open field it will travel along the wooded area instead to avoid being eaten. This is known as observational learning. This is an important adaptation for survival in the wild. It allows the animal to avoid errors that are made by others of its species.

A few studies focused on a lizards ability to visually discriminate from something that is real and something that isn’t ². A video display of male lizard during mating season was shown to captive lizards. The captive lizards would show mating aggression and displays to the video version of other male lizards of the same species. This indicated that the lizards could not visually discriminate between a real lizard and one that was on a screen.

Monitor lizards have the ability to be trained to do certain tasks. One of the easiest things to teach a monitor lizard is target training. We can shape their behavior in such a way that by touching a target they will get a food reward. A zoo has trained a Komodo Dragon to get up on a log and sit patiently while it is being examined by a veterinarian³. Komodo Dragons are also known to “play” with different toys for no benefit other than to just have fun. A good movie that illustrates the intelligence level of monitor lizards is Lizard Kings: On the Trail of Monitor Lizards.

Monitors are intelligent and crafty. They may not have the same abilities as mammals or birds but they can learn new things. When I look into the eyes of a monitor lizard, I see an animal that is looking back in such a way that the monitor is trying to figure me out. It’s not a glance rather a deep stare into who or what I am. We should give lizards more intellectual credit than we do.

 

 

ReptileRanger.com teaches how to target train a monitor lizard

References

1.         Leal, M. & Powell, B. J. Behavioural Flexibility and Problem-Solving in a Tropical Lizard. Biol. Lett. 8, 28–30 (2012).

2.         Vonk, J. & Shackelford, T. K. The Oxford Handbook of Comparative Evolutionary Psychology. (Oxford University Press: 2012).

3.         Kaufmann, G. Lizard Kings: On the Trail of Monitor Lizards. (PBS: 2009).