Western Fence Lizards - Benefits for Humans?
By Rachael Lloyd
These animals are so ordinary and abundant that everyone is familiar with them even if they don’t know the name. The wide-ranging Western Fence Lizard, Sceloporus occidentalis, is a common lizard especially prevalent in the American Southwest and Northern Mexico. In Southern California its familiar presence in Bolsa Chica, in backyard gardens, in vacant lots, and yes, scurrying up fences, is so ubiquitous that it is glanced over without much reaction or notice. From a normal five to ten foot viewing distance the dusty gray wiggly little fellows might even provoke a bit of a yuck reaction similar to a snake sighting—if it gets a reaction at all.
The little grayish fellows attract a bit more notice from March to June each year if they are truly males. During mating season males will often perch themselves on block walls, high rocks or dead logs and pump their upper body up and down in an attempt to interest any nearby females who might be waiting to be impressed. Move in for a closer look and among the dust covered black, gray and/or tan scales patterning its back is a scattering of blue or blue-green scales. Turn the lizard over (if you can catch it) and if it is a male, the underbelly will be marked with an astonishingly bright blue. Males’ engage in rhythmic push-ups in order to display this belly and chin coloration. While hard to see in nature, it is easy to find close up images of these distinctive under markings on the web and especially at http://calphotos.berkeley.edu.
As surprising as the skin colorations are even more surprising is a feature of the Western Fence Lizards’ blood biology. In California, Western Black-legged Ticks, also commonly known as Deer Ticks, are the primary carriers of Lyme disease. These ticks frequently feed on Western Fence Lizards by attaching themselves around the lizards’ ears to ingest its blood. Research has revealed that a protein in Western Fence Lizard blood kills the bacterium transmitted by ticks infected with Lyme disease. In addition to protecting the lizard itself the blood inside of the ticks’ gut is cleansed through digestion and the ticks no longer carry Lyme disease. Due to this benefit studies have shown that Lyme disease is lower in areas where Western Fence Lizards occur including California.
So far this blood protein has not been adapted into a vaccine to prevent Lyme disease in humans but the possibilities are intriguing. Nature is a master chemist and has served as the inspiration for numerous drugs on the market today. As you are hiking the trails through Bolsa Chica and spot these common reptiles remind yourself that respect for even the ordinary things of nature has its rewards. Every living thing has qualities that are exceptional and might even someday profit us personally.