lizard threat displays

Even if you’re not interested in lizards, stay with me for a minute or two–because this is a mystery of nature.

This lizard is an Australian bearded dragon. He thinks his reflection in the mirror is another lizard, so he goes into a head-bobbing display to warn the stranger off his territory. He even has some idea of going behind the mirror to see if the interloper might be hiding there.

Travel halfway around the globe to, say, Florida, and you’ll find little green anoles performing the same display for the same reasons (courtship and threat). These groups of lizards are not related, and thousands of miles of planet lie between them. Behavior doesn’t show up in any fossil record. Why do these very different, widely separated lizards do this same ritual?

God’s work is endlessly fascinating: you never get to the bottom of it.

Meanwhile, I’ve had many different kinds of lizards as pets and by rights some of them should have head-bobbed (also known as lizard pushups)… but none of them ever did. I did have an anole who went totally ballistic when he saw his reflection in a hand mirror; I had to take the mirror away before he did himself a mischief.

Then there are the two large families of lizards, one in the Old World, the other in the New, who look just about exactly like one another but aren’t related at all. But that’s another post for later sometime.

Jambo, boys ‘n’ girls! Mr. Nature here, with the humble fence lizard. My home state of New Jersey is but poorly endowed with lizards, but we do have the Eastern Fence Lizard, one of my favorites. The lizard in this video is a Western Fence Lizard from California, almost the same thing.

The “push-ups” that these lizards do, mostly the males, is a territorial display. It means “get lost!” Most of the lizards in the iguanid family–dozens and dozens of species–make this display, as well as puffing themselves up, showing the dewlap, etc. There are even some Old World agamid family lizards that do push-ups. This is a mystery to me, that totally unrelated lizards should resort to the same threat display.

I once had fence lizards and one of the females laid eggs. We caught her doing it, and so were able to contact the Staten Island Zoo for instructions as to how to care for the eggs. They were good instructions, and all two dozen eggs hatched into absolutely perfect little lizards.

At night the little ones used to bury themselves in cedar shavings with only their heads left showing. One morning our granddaughter came into the living room and saw them like that–only the tiny heads scattered here and there–and totally freaked out. She was sure some fiend had come in the middle of the might and beheaded the baby lizards. But Mrs. Nature was quickly able to reassure her otherwise.

Fence lizards eat live bugs and can be kept together in an aquarium without your having to worry about them assassinating one another. They tame rather quickly and are altogether nice lizards.