Tinker Air Force Base, located a few miles east of Oklahoma City, has long been celebrated as the military’s largest air defense depot and is home to a number of very large, very impressive planes. But just off the runway, in the base’s grassy natural reserves, lives another equally impressive, albeit physically smaller, claim to fame: Texas horned lizards.
Tinker Air Force Base is home to a stable population of about 50 Texas horned lizards. Research teams working on base have made significant contributions to our knowledge of the species and its habits since a long-term study began in 2003.
“Texas horned lizards occurred on this land long before the first Airmen arrived and have amazingly survived right alongside them as they perform their critical Air Force mission,” said Ray Moody, natural resources scientist for the base and long-time advocate for Texas horned lizards.
Moody has been leading the charge for the base’s lizard conservation program, including the research and survey efforts that officially began in 2003. Twenty years later, Tinker AFB is now considered to have the longest-lived Texas horned lizard study, and one of the most-studied lizard populations.
“There’s always something new to learn,” Moody said. “When you answer one question, find out one new thing, it leads to even more questions.”
Moody’s first question arose in the early 2000s when he was completing an environmental impact assessment for a proposed natural gas pipeline that would be installed along the edge of the base’s known lizard habitat. Moody used radio telemetry to track the lizard’s whereabouts and learn how to mitigate the potential impact of the project.
Research teams have tracked more than 1,150 individual Texas horned lizards at Tinker AFB since the first study in 2003. A transmitter is glued to this lizard’s back and an elastic collar is around the neck.
“Initially, we were just trying to figure out the best thing to do for the lizards.”
From that first study, and with improvements in technology, Tinker’s lizard tracking efforts have expanded, and more than 1,150 individuals – adults, juveniles, and hatchling horned lizards – have since been tracked using a combination of radio telemetry, cellular tracking technology, and harmonic radars, a device similar to what is sewn into ski jackets to locate avalanche victims.
The inch-long hatchlings are too small to carry most tracking devices, so very little was known about the youngest lizards until the harmonic radar tags were incorporated in the study. With the smaller, surprisingly inexpensive tags, researchers were able to learn about the hatchling’s hibernation habits.
“That’s probably the biggest advancement in the past 20 years – being able to track the little hatchlings and learn about their biology.
“We knew the adults were hibernating about a half-inch under the soil. But in the last decade, we’ve learned that the hatchlings are hibernating aboveground. They’ll get in little groups and lay on the ground, sometimes one on top of another, all through the winter,” Moody said. “When we’ve detected movements of the hatchlings in early spring, we’ve wondered if they’re actually waking up, or if they’ve just been moved by a strong wind.”
While tracking has been a continuing focus in the last 20 years of study, research teams have also answered questions about the lizard’s habitat use, behavior, diet, potential for translocation efforts, survivorship, and even their predators.
Tinker’s Lizard Highlights
- The lizards emerge from shallow hibernation sites around April 1, plus or minus 10 days. Egg-laying begins in June. Clutches of 13-20 eggs hatch in August. Adults begin going dormant in September or October, preferring to spend the winter about a half-inch underground on grassy, south-facing slopes.
- Each lizard uses about 2 acres of space. Daily movements can increase to about 25 meters during reproductive periods. Tracked lizards are often associated with the base’s graveled nature trails.
- The base’s lizards are known to eat ants from more than 12 different genera.
- Lizard activity peaks between 75- and 91-degrees Fahrenheit.
- Adult annual survival is estimated at 47%. About 33% of hatchlings and 25% of juveniles survive to the next year.
- Lizards mature and reproduce in their second or third year.
“We never know what to expect. We’ve tracked signals to the tops of trees and to the middle of a pond – birds had apparently fed on the lizards and left the tracking devices in nests and on pond snags. And we’ve tracked signals of lizards that have been eaten by snakes. That’s how we documented the first copperhead on base.
“We even have x-rays of a speckled kingsnake and know that individual snake has eaten at least four transmittered lizards. It’s amazing that we can even know that.”
Healthy Lizards = Healthy Ecosystems
Beyond answering questions about the lizard’s life, Moody and others in Tinker’s Natural Resources Program have also focused on improving habitat and maintaining healthy ecosystems. The team has worked to make sure enough native grasses, bare ground, and ant colonies are available in the base’s natural reserves – areas that have been set aside for wildlife and outdoor recreation opportunities like hiking and fishing – for the lizards to continue to persist on the base.
“John Krupovage, our natural resources manager, has really championed that aspect of the project. The lizards have to have the right ingredients to survive, and we’re managing these natural reserves to provide those ingredients.”
Mowed areas of turfgrasses have been converted to stands of native prairie, and a fire team has been created to burn the reserves within prescribed conditions on a regular basis. These habitat practices not only help the lizards by providing extra habitat, but they also help reduce base maintenance costs.
“We want to be good stewards of the land. But maintaining healthy ecosystems doesn’t just help the lizards. It also helps the military. We need to have the land to fly the airplanes. We need to have functioning creek systems to drain the base. Without a healthy ecosystem, we would start having access problems and not be able to meet our mission.
TINK the Mascot Celebrates Base’s Conservation Program
Tinker Air Force Base recently named TINK, an aircraft mechanic and Texas horned lizard, as its official mascot, highlighting the base’s 20-year lizard research efforts and conservation history.
TINK’s character story not only calls attention to the long-running conservation program but is also a reminder that Airmen can live and work together with the environment while supporting the Air Force Mission. Named for Maj. Gen. Clarence L. Tinker, the highest ranking Native American officer and first general lost in action during World War II, TINK lives in the tall grass outside Tinker’s runway and has always dreamed of becoming an Airman. Eager to learn, TINK ventures beyond the base’s natural reserves to discover how to support the warfighter. During his journey, he learns the importance of aircraft sustainment and sets out to be the best aircraft maintainer at Tinker. TINK wants to teach people about the aircraft sustainment and the innovations that keep the warfighter going and travels all around Oklahoma with his jet pack to spread the word.
Many Hands Make Light Work
Twenty years after the first transmitter was deployed, Moody is amazed to look back and see how far Tinker’s lizard program has grown.
“I would never have thought we would still be talking about horned lizards,” Moody said. “Our partners have really made this possible. From college students to the Oklahoma City Zoo, to the support of multiple universities and agencies, to the many additional local and regional organizations, our partners have made this research project long-term, significant, and possible. Its success is rooted in collaboration and sharing.”
A large umbrella grant, administered by the U.S. Army Corps of Engineers Construction Engineering Research Laboratory has paved the way for many of these partnerships, making it easier to collaborate with universities and manage the necessary cooperative agreements. Another partnership with the Air Force Civil Engineer Center and Colorado State University Center for Environmental Management - Military Lands has provided weekly maps of the lizard’s movements. And a 16-year partnership with the Oklahoma City Zoo has provided thousands of hours of tracking and support.
Tinker’s lizard conservation program relies on many partnerships. Tom Miller, a Geographical Information System Analyst with Colorado State University, provides weekly maps of the lizard’s movements and helps with an end-of-the-season round-up of transmittered lizards.
All told, more than seven theses and dissertations and 20 peer reviewed findings have been published by the research teams since 2003, sharing the results of Tinker’s lizard studies with the scientific community. And dozens of media features and articles, including a front-page story in the LA Times, have helped share the story of this unique population and its many dedicated supporters.
“All of this work feeds into our overall base plan, our integrated natural resources management plan,” Moody said. “There are so many parts to this one project, and with our partners, it really just comes together.”