A Thorny Problem

A Thorny Problem

Horned lizard 017Horned lizards, commonly called “horny toads”, used to be a common sight in most of the United States. Children of previous generations may have even had one as a pet, these days it is illegal to posses them.  Texas is home to two species; the Texas Horned Lizard (Phrynosoma cornutum) and the Short Horned Lizard (Phrynosoma hernandezi). They are both listed as threatened by Texas Parks and Wildlife and a “Species of Concern” by U.S. Fish and Wildlife. The Endangered Species Act provided a category known as “C2” which gave limited protection to species that U. S. Fish and Wildlife considered at risk. That category and its protections was eliminated in 1996.

The Wildlife Center receives several of these interesting animals each year. While the Greater Houston area could support isolated populations, these animals were probably “pets” that were surrendered or “set free” to be found by others. The “lucky” Horned lizard arrives at the Wildlife Center dangerously dehydrated and malnourished. Horned lizards are very specialized eaters and as such are exceedingly difficult to maintain in captivity. Their status as threatened by Texas Parks and Wildlife requires Wildlife Rehab and Education notify authorities upon admission.

First introduced to Europe in 1651 by the Spaniard Francisco Hernandez, they were considered sacred by the indigenous Indians. Astounded audiences were regaled with stories of blood jetting from the eyes. Fourteen sub-species have been described and eight can be found in the United States. Australia has its own spiny lizard called the Thorny Devil. Biologists originally thought they descended from a common ancestor, but genetic analysis has shown that the two lizards are examples of convergent evolution. Lizards on the two different continents independently evolved similar adaptations to exploit a biologic niche.

Some species of Horned lizards can really squirt blood from their eyes. In fact they can control the direction of the stream. The Horned lizard’s first line of defense is protective coloration; the spiked profile further disguises its outline. The lizard’s initial reaction to threats is to flatten against the ground and freeze. When it decides to flee, brief bursts are followed by another freeze. Based on the reaction of feline and canine predators to the blood, it must taste revolting. Unfortunately, other predators aren’t affected by the blood. To thwart other predators, the Horned lizard has evolved dramatic spiked armor. In addition, the Horned lizard can puff up its body to make it look more intimidating.

Some species like raccoon, opossum and squirrel co-habit and even flourish around humans, others such as the Peregrine Falcon have found niches but the majority still require specific habitat. The Horned Lizard is particularly sensitive to changes and quickly dies out when humans change their habitat.  Destruction of habitat and conversion of habitat to agriculture coupled with the accidental importation of the fire ant have decimated their numbers. The Horned Lizard is especially picky about dinner, the harvester ant comprises 60 – 90% of their diet.  The fire ant aggressively competes for territory and food sources quickly displacing or killing native ants. Humans have compounded the problem in their quest to rid their environment of this stinging menace by using insecticides that indiscriminately kill both the target and beneficial ants.  

Aggressive collection of these fascinating lizards for the pet trade further pushed it towards extinction. Despite its fierce appearance, the Horned lizard is docile and people cannot resist picking them up and bringing them home.  Every summer, once the kidnapped lizards quit eating or look sick, research into their diet will reveal their protected status. Now they realize they have a species that is illegal to possess. Oops, what now? The Wildlife Center hopes that the mistake isn’t compounded by letting the animal die. WR&E will restore surrendered animal to health and transfer it to someone with the proper permits.

Sometimes the cause of an animal’s decline can be determined. Horned lizards are still an enigma. It’s easy to see what is missing from a particular habitat, but why do they thrive or disappear in what appears to be equally hospitable locations? Active conservation cannot occur without this knowledge. Texas Parks and Wildlife is asking for your help. Click here to learn more.

Receive Updates

No spam guarantee.

About the Author:

Leave A Comment