WILDLIFE WEDNESDAY: Psychedelic Summer Lizard
Iguana tell you about a Twentynine Palms Icon
Although it has been stupid hot for a couple of weeks now, a few flowers still bloom. Creosote’s tiny puffballs hang from branches, lavender blossoms cling to desert willows, and palo verde trees have just now burst into flower.
Flower-loving, heat-seeking lizards like desert iguanas are also still around, climbing creosote bushes to nibble flowers, basking on hot rocks, and flicking down burrows to hide from passing humans. Desert iguanas like it when it’s 110 degrees, hanging out on the front porch and gobbling crickets I find in the house and toss to them. (They’re like a college friend I had: vegetarian except for cheeseburgers.)
Desert iguanas can’t seem to get hot enough and can often be seen basking on asphalt roads. Driving out of the park one evening we saw a desert iguana whisking away, but not fast enough. I swerved to miss it, coming a little close to an oncoming car. While my passenger covered his eyes in terror, I shouted, “lizards rule!” I’m not sure he’s forgiven me.
Desert iguanas possibly have the fanciest pattern of any lizard in the Mojave, which Chuck Caplinger captured in his mural on the Smoketree building on Highway 62 in Twentynine Palms. The dots and dashes seem to reverse themselves: cream spots on a brown or gray background merging into chocolate dots on vanilla. It’s possible to confuse a young desert iguana with another heat-loving lizard: the zebra tail.
Desert iguanas ooze secretions from pores on the underside of their thighs that fluoresce, which the lizards can see and smell, making the desert where they live one vast psychedelic black-light painting. The iguanas leave fluorescent trails that mark territory or let other iguanas know they are around.1
Many flowers have fluorescent markings visible in the ultraviolet spectrum that hummingbirds and pollinating insects can see, and it is believed that desert iguanas see these markings too and look for these cues to find flowers to eat.
I went out with a UV flashlight to look for these desert iguana tracks around a creosote where I know our porch iguana hangs out, but I didn’t see them. I did see a scorpion, though. I will keep trying to get a photo of psychedelic fluorescent lizard trails, and if I do, I’ll post them here.
If you are as fascinated by this as I am, here’s a 1989 New Scientist article all about the desert iguana’s fluorescent pheromones.
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Lizards do rule! We like to watch them doing push ups on our front rocks. We call it the Lizard Gym.