The “Nature Detective” section of a recent mailing from Boulder County Parks and Open Space reminded me how much I like lizards. Apparently in the county we have only 3 small species; out of a world population of thousands. Lizards are the most common reptile on Earth. Ours are shy, harmless carnivores, favoring insects, larvae and ants. They hide in plain sight with their camouflage coloring, but are easily spotted when moving or basking on a man-made surface…like this most common lizard, the Red-lipped Prairie Lizard, a sub-species of a group commonly called Eastern Fence Lizards.
The red lips and blue dorsal colors are obvious on the males during mating season. When defending their turf against other males, trying to attract a female or just trying to look fierce, they do quick push-ups and flatten their bodies.
Females are more relaxed. They lay from 4 to 8 eggs, once or twice a season. Lizards are favorite prey for many animals including snakes, birds, cats, canines and other lizards.
Their skin is dry and scaly. Tough scales protect them from abrasions from rocks, cactus and other spiny plants populating their normal habitats. Scales also prevent moisture loss when it’s hot and dry. Lizards are ectotherms (cold-blooded), so they bask in the sun to warm up. When it gets too hot they must seek shelter under rocks or vegetation, or die.
Prairie lizards and Racerunners lose their tails easily if they are grabbed by a predator. The dropped tail portion continues to twitch, hopefully distracting the predator long enough for the lizard to escape. The one pictured above has grown a new tail. New tails have a cartilage center as the original bones don’t regrow and it doesn’t have the same nice colors.
The second of our locals is the Six-lined Racerunner. These are very hard to spot or very rare, I’m not sure which. racerunner head 7851This is the only one I’ve ever seen and just happened to have a camera along. Here it is emerging from the grass. I’m not sure which of us was more surprised. These are very fast lizards with long whip-like tails. They swing the tails around for balance as they skitter around after grasshoppers, crickets, beetles, adult and larval butterflies, moths, ants, and spiders. they also eat caterpillars and small snails. Their scales are much smoother than the prairie lizards. Their speed, green color and linear stripes help confuse hungry predators. Females are attracted to the most colorful males.Our third lizard is the Short-horned Lizard, frequently called a Horny Toad, although it is definitely not a toad. Their wide, flat bodies with spines at the back of the head and a row along the flanks, makes these small (maximum length 6 inches) lizards hard to mistake. They rely on cryptic coloration for safety. Their preferred habitat corresponds with cattle range land. As long as these areas aren’t sprayed with pesticides to control grasshoppers, the little lizard populations thrive. Babies are about the size of a nickle. Their favorite food items are ants, and they can be seen lapping up a trail of ants one after the other. They don’t drop their tails like the others, but they do jab their horns into whatever animal grabs them and they can squirt blood from near their eyes up to three feet. The blood apparently burns the mouths of would-be predators such as foxes and coyotes. All reptiles shed their skins as they grow. Lizard skin can stretch some, but when it stretches as far as it can, the animal must shed it in order to grow larger. The bright new skin hardens as it dries and is loose to give the lizard room to grow before it has to shed again.
All these lizards have excellent eyesight. They have eyelids that can blink to clean the eyes. They hear well through ear slits on the sides of their heads, and they “smell” by flicking their tongues to pick up scent molecules in the air which they place on decoding organs in the roof of the mouth. They stay underground during the cold months. They are amazing little creatures we share our environment with: often unknowingly. Keep a look-out this summer for your own local lizards.