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Leapin’ Lizards! Is the Texas Horned Lizard Making a Population Jump?

Leapin’ Lizards! Is the Texas Horned Lizard Making a Population Jump?

It is the state reptile of Texas and wears a crown of horns, but a lofty title and royal visage has not prevented the Texas horned lizard from becoming a threatened species. Colloquially known as a horned frog, horned toad, and horny toad, the horned lizard is neither frog nor toad but, thanks to its wide, flattened body and scientific name, Phrynosoma, which means “toad-body,” the nick-names have stuck. With its spiked crown, ability to inflate its body like a spiny balloon and shoot a stream of blood from its eye, the Texas horned lizard would look quite at home on Game of Thrones, but this actually quite docile amphibian is not at all aggressive. Indeed, it may just lie limp and play dead when held, one of the reasons so many were captured and kept as pets which, along with habitat loss and pesticide use, is among the most popular theories for population decline. Today, it is illegal to keep a horned lizard without a state permit.

While its numbers may have dwindled, the Texas horned lizard has never strayed far from the public eye. From Our Toad to Ruin, an in-depth article in the June 2015 Texas Monthly that is well-worth the read: “They’re on our license plates, they’re our school mascots. They’re our state reptile. But when was the last time you saw a horny toad in the wild? The mysterious disappearance of Texas’s most beloved critter and the desperate attempts to save it.” And, in a May 2015 piece on TexasHillCountry.com, The Comeback Lizard explores horned lizard wildlife management efforts at McGillivray and Leona McKie Muse Wildlife Management Area (the Muse WMA in Brown County).

So, are all spiky crowns pointing to a horned lizard revival? While there are some reports of a horned lizard population rebound, there is still much to do for this surprisingly sweet, sun-basking amphibian. Along with overharvesting for the pet trade, the decline in horned lizards is blamed on loss of habitat by agricultural and urban conversion, overuse of pesticides, and the spread of red imported fire ants. Both the pesticides and fire ants have seriously impacted the population of harvester ant which is the horned lizard’s principal source of food. So, what can we do to help?

Five Ways to Manage for the Texas Horned Lizard

While three horned lizard species call Texas home, Greater short-horned lizards, Round-tailed horned lizards, and Texas horned lizards, it is the latter that occupies more of the state which, today, means primarily South and West Texas. Briefly stated, according to Texas Parks and Wildlife, “they can be found in arid and semiarid habitats in open areas with sparse plant cover. Because horned lizards dig for hibernation, nesting and insulation purposes, they commonly are found in loose sand or loamy soils.”  Does your property have habitat characteristics consistent with that favored by Texas horned lizards? If so, here is a round-up of the top five management recommendations based on Management of Texas Horned Lizards by Scott M. Henke and Wm. Scott Fair to get your Texas horned lizard wildlife management efforts started.

1) CONDUCT A SURVEY

Because the distribution and abundance of Texas horned lizards in Texas is unknown, a survey of your property is key, even if you believe that your property is not optimal horned lizard habitat. Not finding horned lizards may shed light on why they are not found in that particular area. Surveys should be conducted between May 1 and September 1 during the mid-morning hours on clear days when temperatures are above 75 degrees. During the surveys (you should aim for at least 3 counts), you’ll be counting Texas horned lizards, harvester ant mounds, and fire ant beds. For details on how to effectively conduct a survey on your property, see Management of Texas Horned Lizards. Landmark Wildlife can also assist in horned lizard surveys, contact us for details.

2) AVOID LIVESTOCK OVERGRAZING

Overgrazing by livestock on rangelands may substantially reduce cover needed by horned lizards for thermoregulation or to escape from predators. Previous overgrazing was noted as one of the possible reasons for the absence of horned lizards at the Muse WMA.

3) AVOID THE USE OF BROADCAST PESTICIDES

Another commonly cited reason for population decline is the use of pesticides, not only capable of killing horned lizards directly as a toxin, but also indirectly by killing harvester ants which comprise a whopping sixty percent of the horned lizard’s diet. If pesticides must be used, to combat fire ants for example, then spot treatment is recommended rather than broadcast pesticide application

4) WATCH THE ROAD

Like many Texans, Texas horned lizards love to hit the road. They often use secondary roads for resting and bedding sites. Two ways you can help here is to avoid disking or grading roads during the active period of horned lizards, from mid-March through mid-October. Road maintenance can not only kill them directly, but uncover them and expose them to predators. You can also limit your driving on secondary roads during peak times of horned lizard activity. Studies have shown that vehicular accidents were a significant mortality factor of horned lizards. Suggested times for taking particular care on secondary roads include late afternoon to sunset in April and May, while morning hours in June and July may result in a greater number of lizard encounters.

5) IMPROVE HABITAT

As in most wildlife management, success almost always comes down to habitat improvement. For horned lizards, creating small, cleared spaces not only provides direct access to sunlight, needed to help maintain optimal body temperature, but  newly-fertilized harvester ant queens also seek open areas to establish new colonies. Not unlike the quail and other wildlife, horned lizards like a mix of open areas with cover to not only heat and cool as needed, but cover also provides a place to avoid predators. Planting and fostering native bunch grass such as buffalo grass allows horned lizards to easily move among the grass clumps, versus carpet grasses whose thick mat that can impede horned lizard movement.

All in all, it feels like something positive is in the air – and on the ground – for our state reptile. Not only are we valuing them in theory – on license plates and as school mascots – but more of us appear to be making efforts to value them in reality. Taking steps to help the horned lizard is not only creating good horned lizard habitat, it is creating good wildlife habitat ― an easy wildlife management leap for landowners.

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