Wild About Texas: Cloning is nothing new for Checkered Whiptail lizards

Over the past several years scientific technology has advanced tremendously. Although most of the advancements have proven to be beneficial in their own right, there are consequences to all advancements, and some are downright controversial.

One such controversy is the technology of using DNA to clone organisms. However, as is often the case, the natural world has “beat us to the punch” by having its own examples of cloning. One example can be found in two separate populations here in Texas.

The Checkered Whiptail (Aspidoscelis tessellata) is a rather large and fairly common lizard that has a curiously disjunct range in Texas. It can be observed in the Trans-Pecos region west of an imaginary line drawn from the Midland area southeast to near Del Rio. There is another population in the northwestern Texas Panhandle, with the Palo Duro Canyon (where it is extremely abundant) being its eastern apex of distribution. It prefers to live in dry washes, rocky plains and rocky scrublands, although floodplains with sandy soil are also selected.

This variety of Whiptail lizard is one of 10 species of the genus that resides in Texas, and it is by far the largest race. Adults of this species can approach 15.5 inches in total length, with remarkably long tails. Hatchlings are large as well, usually approaching 5 inches in total length at hatching.

The Checkered Whiptail is appropriately named in that its dorsal pattern is tan, yellow or light brown and is adorned with large, vertical black bars. The configuration of these bars can be arranged in some specimens to where you can see light stripes running longitudinally down the body. The legs and tail are heavily mottled with spots.

As mentioned in the first paragraph, this lizard species has a unique way of reproduction because it is an all-female species! During the breeding season, these lizards engage in a pseudo-courtship where one lizard will take on the role of a male while another female is ovulating, courting her with head bobs and leg rubs. However, throughout this process there is no sexual contact. The female lays a clutch of three to eight eggs a few weeks later, and the young lizards hatch as identical clones of their mother after an incubation period of six weeks. The process of an all-female species reproducing clones is known as parthogenesis.

Checkered Whiptails are very wary and are generally active during the heat of the day, even after temperatures have risen above what most other ectotherms find tolerable. They are voracious feeders of insects and arachnids and can be quite comical to observe as they forage for their prey. They will oftentimes walk slowly, watching for prey, then will make erratic bursts of speed to another spot nearby that they feel may be more productive. They also use their front legs to dig in sandy soil and leaf litter to uncover prey.

Although large, they can be quite hard to observe as anything other than a dash across a trail because they are so wary. Patience is the key to positively identifying this unique species.

Michael Price is owner of Wild About Texas, an educational company that specializes in venomous animal safety training, environmental consultations and ecotourism. Contact him at wildabouttexas@gmail.com.