Observations in Nature: The Tucson Banded Gecko by John R. Leeper
Whether we like it or not, we are the interlopers in the Sonoran Desert. The native residents present themselves to us daily as a roadrunner dashing across the road; as an emerald hummingbird darting from one flower to the next; as butterflies in a rainbow of colors fluttering and floating from plant to plant; or, disturbingly, as a rattler on our front doorstep. And, there are the coyotes calling through the darkness; one starting its night’s song followed by others, creating an eerie choir.
I recently discovered a handsome native houseguest in my garage. At first glance, with its black bands, I thought it was a baby Gila Monster. But, no, the tail was too long and it was too fast on its feet. A quick cell phone snapshot provided a photo to compare with those on the Arizona Herpetological Association web site (http://www.azreptiles.com/reptiles_of_az.php?type=Lizard). My visitor was a Western Banded Gecko, Coleonyx variegatus. Further web searching revealed that my visitor was a subspecies, the Tucson Banded Becko, Coleonyx variegatus bogerti.
Subspecies are the taxonomic designation or classification below that of species. Subspecies are geographically separated from other members of the species. One subspecies is capable of interbreeding with other subspecies, which in the wild, may occur at the periphery of overlapping ranges. A subspecies also possess some taxonomic trait that distinguishes it from other members of the species.
The Tucson banded gecko possesses several taxonomic traits that distinguish and differentiate it from other members of the species. Male Tucson Banded Geckos have eight or more pre-anal pores while other members of the species are limited to seven or fewer pre-anal pores. These pores excrete a waxy material containing pheromones used to mark the male’s territory and to attract and court females. Markings also distinguish the Tucson Banded Gecko from other members of the species. The edges of the dark wide body bands of this subspecies are darker and the head is conspicuously spotted when compared with other members of the species.
The full range of Coleonyx variegatus extends from Southern California and Baja, Mexico in the west to southwest New Mexico and northern Sonora, Mexico in the east and north into Nevada and Utah. The species was first described by Baird in 1858 and divided into five subspecies by Klauber in 1945 based on distinct taxonomic characters and geographic distribution. Geographically, the range of the Tucson Banded Gecko is limited to extreme southwest New Mexico, upper Sonora, Mexico and southeast Arizona. In Arizona, Coleonyx variegatus bogerti can be found in Maricopa, Pima, Pinal, and Santa Cruz Counties with Pima County being at the center of its range.
It was not until the late twentieth and early twenty-first century that taxonomists removed lizards in the genus Coleonyx from the gecko family Gekkonidae and placed them in the family Eublepharidae (subfamily Eublepharinae). This move was based primarily on two taxonomic characteristics. Unlike species in Gekkonidae, lizards in the genus Coleonyx lack adhesive toe pads and possess moveable eyelids. Perhaps the most interesting similarity of the Gekkonidae and Eublepharidae is their ability to vocalize.
The scientific name of the Tucson Banded Gecko has meaning. Coleonyx is a mixture of Greek and Latin words with a combined meaning of sheathed nail or claw. The species name, variegatus, comes from the Latin word for variegated and refers to the banding on the lizard’s body. And, the subspecies name, bogerti, is in honor of Charles Mitchell Bogert, who was a distinguished herpetologist at the American Museum of Natural History.
The Tucson Banded Gecko is an attractive animal. Its body color runs from a pale tan to creamy yellow with distinct broad dark bands and spots while the legs and feet take on a rosy pink hue.
Adult Tucson Banded Geckos can grow up to six inches in length with half of the length being in the tail. The tail has a couple of interesting attributes. It is the major fat storing organ that provides the lizard with nutrition during its winter hibernation. And, the lizard can use its tail as a defense mechanism. When confronted by a predator, the Tucson Banded Gecko can raise and curl its tail over its back to make it look larger or be confused with a scorpion. If this confusion ploy does not work, the lizard can lose its tail to writhe and wiggle on the ground to distract its predator while the rest of the lizard scampers away. No worry, the lizard has the ability to regenerate a new tail.
Tucson Banded Geckos are terrestrial, nocturnal predators active between April and October and hibernate during the colder months, between November and March. During the months they are not hibernating, they spend the daylight hours in shady, protected areas to avoid the day time heat and exposure to the sun. Tucson Banded Geckos emerge in the evening to prey on such delicacies as small insects, spiders and even baby scorpions. And, their prey appears to provide the lizards with their moisture or water needs.
Female Tucson Banded Geckos can lay up to three clutches of two soft-shelled eggs in a summer season with peak egg lays in the months of May and June. The female can retain the sperm from an earlier mating to fertilize eggs in a later clutch. It normally takes an embryo 45 days to fully develop and hatch. Hatchling lizards are about an inch long and reach maturity the following season. And, Tucson Banded Geckos have been recorded to live more than 15 years.
The Sonoran Desert is composed of many plant communities and Coleonyx variegatus bogerti can be found in all of them present at elevations between 2,500 and 5,000 feet. The Tucson Banded Gecko population does not appear to be endangered or threatened at this time, but the encroachment of humans will continue to restrict their native habitat. Nevertheless, as with all of the desert’s native plants and animals, it is best to leave them be.
For those interested in more information on the Tucson Banded Gecko, conduct a web search on Coleonyx variegatus bogerti.
