CONTACT: Julie Martinez
512-593-2590 or
Dr. Alan Fedynich
512-593-4130
TEXAS A&M-KINGSVILLE STUDY LOOKS
AT DECLINE OF HORNED LIZARDS
KINGSVILLE (June 16, 1998) -- In Texas the law says it's illegal to pick up, touch or possess a horned lizard and why anyone would want to is beyond comprehension to many. But despite the tough exterior of these spiked creatures, there has been a decline in their population over the past two decades.
While many Texans have fond memories of finding the Texas horned lizard or 'horny toad' in their backyard as they were growing up, population decline of the reptile has made that a rarity today.
Dr. Scott Henke, associate professor in the animal and wildlife science department at Texas A&M University-Kingsville, has been studying the disappearing horned lizard for the past six years.
"We really cannot pinpoint an exact reason why the Texas horned lizard is declining in Texas, but some potential explanations include the increase of fire ants, use of insecticides,
exploitation by the pet industry and changing environmental conditions," Henke said, who also works with the Caesar Kleberg Wildlife Research Institute.
Fire ants are believed to out-compete native harvester ants for food and space. "Harvester ants are the preferred food of the Texas horned lizard and if the food resource declines, lizard
numbers will also decline," he said.
Insecticides could be detrimental to horned lizards directly by causing illness and death and indirectly by severely reducing or eliminating their food source, Henke added.
In the past, Texas horned lizards have been collected for the pet industry, by Boy Scout troops for trading at jamborees, for the curios trade and by tourists to take home and show friends.
"Some researchers have suggested that Texas horned lizards have declined because of the loss of habitat from urbanization, suburban sprawl and an increasing trend to convert native rangelands to agricultural crops," Henke said.
"There does not appear to be any one single reason for their statewide decline," he said. "Most likely, it is a combination of these factors that is causing the decline in the population of the Texas horned lizard."
The state of Texas placed the horned lizard on the threatened species list 20 years ago making it illegal to pick up, touch or possess the fading reptile.
Through Henke's research and help from Texas A&M-Kingsville graduate students, more is known about the animal's basic ecology. "We know a lot more about this species than we did a decade ago," he said. "Researchers now have basic information about habitat characteristics and preferences, which can be used to develop recovery management plans."
"Research by the Texas Parks and Wildlife Department on the Chaparral Wildlife Management Area, under the leadership of David Synatske, have added to our knowledge of Texas horned lizards," Henke said. TPWD employees Melisa Montemayor and Chip Ruthven have been studying population dynamics and horned lizard movements for the past seven years.
Texas horned lizards have been called horned toads or horned frogs, but they are, in fact, lizards. Toads and frogs are tailless amphibians that live in land or water. Toads have rough, warty skin and frogs have smooth skin. Horned lizards are reptiles with tails and a scaled body.
There are currently 13 species of horned lizards, three of which are found in Texas.
The Texas horned lizard can be distinguished from other species of horned lizards by the two very sharp spikes that protrude from the back of their head, two rows of fringed scales on their sides, dark brown to sooty-colored dorsal spots edged with lighter colors and a light-colored stripe down the middle of their back.
Adult Texas horned lizards range in length from three to five inches, excluding their tail. The largest on record measured at more than seven inches from the tip of its snout to the tip of its tail.
Today, Texas horned lizards are found in the southeastern tip of Arizona and Colorado, southern and eastern New Mexico, most of Kansas and Texas and all of Oklahoma. They are apparently doing well throughout most of their range except in Texas.
The current range appears to be decreasing. The Texas horned lizard no longer occurs in Texas east of an imaginary line from Fort Worth to Corpus Christi except for small, isolated populations.
The Caesar Kleberg Wildlife Research Institute recently published a management bulletin by Henke and William Scott Fair entitled Management of Texas Horned Lizards.
"The bulletin discusses what is currently known about the Texas horned lizard and what steps can be taken to help restore this threatened species," Henke said. "Hopefully, by publishing this information, we can create more awareness and get Texans interested in helping this unique reptile."
The bulletin is available by writing the Caesar Kleberg Wildlife Research Institute, Texas A&M-Kingsville, Campus Box 218, Kingsville, TX 78363 or by calling 512-593-3922. Because of the dramatic population decline of the Texas horned lizard and concern over their future, state and private organizations are coming together to help the reptile.
"The more we learn about their biology and ecology, the better we can develop appropriate recovery and management strategies," Henke said. "The Texas Parks and Wildlife Department is sponsoring a program call the Texas Horned Lizard Watch, designed to gather population data from surveys conducted by interested individuals on their property."
For more information on this program and to learn how to conduct horned lizard surveys, contact the Texas Parks and Wildlife Department at 4200 Smith School Road, Austin, TX, 78744.
The Horned Lizard Conservation Society is a nonprofit organization dedicated to the conservation and recovery of the declining horned lizard populations. They publish a newsletter, are active in research and recovery and educate the public about the threatened reptile. They can be contacted at P.O. Box 122, Austin, TX 78767.
"We hope that the efforts generated by concerned citizens and state and private organizations will stop the decline of the Texas horned lizard and young Texans will again know the excitement of finding a 'horny toad' in their backyards," Henke said.
-TAMUK-