As I meticulously slipped a small loop of string over the head of a grasshopper — tentatively gliding it past the antennae — I thought to myself how the day had taken an unexpected turn. I woke up that morning thinking of lizards, yet here I was on at least my 10th attempt to ensnare this insect. 

The grasshopper was only practice for what lay ahead for the day. I volunteered to help Wendy Estes-Zumpf, the Wyoming Game and Fish Department herpetological coordinator, capture lizards near Torrington.  But, the morning wasn’t ripe for tracking them down. An overcast sky draped the area in shadow, and we couldn’t see any lizards darting between sagebrush or resting under debris. When Estes-Zumpf spotted the large grasshopper, she suggested I practice the technique for catching lizards so I would be ready if we spotted one.

The method isn’t like the school-yard cup-and-grab; it’s a lot more deliberate. And there’s a tool — a small loop of string was attached to the end of a telescoping fishing rod. If we spotted a lizard, we would attempt to “lasso” it by slipping the loop over its head and giving a light tug. If done right, the loop would close from the weight of the lizard, and we could snatch it up quickly and remove the loop. It’s a safer method to catch small lizards and less likely to injure them compared to swiping them up with your hands.

After multiple attempts with the grasshopper, I started to feel confident I could catch a lizard. The prairie lizards we were after played an important role in helping researchers properly identify a population of relatives that had long been believed to be a different species.

The events leading up to my day of looking for prairie lizards starts with a misunderstanding — best described as a lack of good information — regarding a population of lizards in the Laramie Mountains. The high altitude-loving reptiles were long believed to be plateau fence lizards related to a population found in southwestern Wyoming near Flaming Gorge Reservoir. The Laramie Mountain lizards looked similar to the plateau fence lizards, but one difference caught the attention of researchers. Males in the Laramie Mountain population sported red lips during breeding season. That trait was not seen in the southwestern Wyoming population, so in 2019 researchers set out to better understand the DNA of these lizards.

Adult male prairie lizards from the Laramie Mountains exhibit red lips during the breeding season. (WGFD photo)

 

Using the same loop technique with a telescoping fishing rod and string, researchers from Game and Fish captured 10 lizards from the Laramie Mountain population.

“These particular lizards are best captured with the lasso technique,” Estes-Zumpf said. “They’re bold, curious and stick to the rocks they’re on, so they aren’t going to run off across the prairie. Sometimes they’ll even bite the lasso as we try to loop it over them. They don’t really run away as much as other lizards.”

Game and Fish documented each capture and logged individual information about each lizard. Then they took a small tail clipping to send to Adam Leaché’s lab at the University of Washington for DNA analysis. This lizard is one of the many lizard species that can regrow its tail, so the clipping doesn’t permanently mar it. After collecting data, the lizards are release immediately.

The results from the DNA were somewhat surprising. These lizards, long thought to be a type of plateau fence lizard, were revealed instead to be prairie lizards like those found near Torrington, even though both their appearance and habitat were different from the population there. The prairie lizards near Torrington have various stripes down the center and sides of their backs, but the prairie lizards in the Laramie Mountains don’t display stripes or have faint stripes.

No one likes being called by the wrong name, and if done for years it just seems rude. But what does it mean to a lizard if people call it by the wrong species name? The lizard may not care, but for wildlife managers it can mean a great deal.

Understanding the population and distribution can greatly impact management decisions. Discovering one  population was a different species changed the lizard landscape in Wyoming. The DNA analysis showed plateau fence lizards are less abundant in Wyoming than previously thought, and prairie lizards — previously thought to be the rarest lizard in Wyoming — are more abundant. However, this new information means there are two distinct populations of prairie lizards in the state: prairie-dwelling prairie lizards near Torrington and mountain-dwelling prairie lizards in the Laramie Mountains. The prairie lizards near Torrington are believed to have a low abundance and limited distribution, so additional monitoring of their population will need to take place. However, the Laramie Mountain prairie lizards appear to be plentiful.

“The prairie lizards in the Laramie Mountains have a robust population,” Estes-Zumpf said. “We did surveys in the burn scar of the Arapaho Fire that burned through the area in 2012 to see how they were affected by wildfires, and the fire didn’t seem to harm them. There aren’t a lot of other threats to their population there, so they seem to be a hardy population of prairie lizards.”

This significant difference in habitat preference, distributions, and appearance means each of these prairie lizard populations should both be managed as separate management units.

With a changing understanding of lizard populations in Wyoming, researchers have more questions about how lizards found in Wyoming and Colorado’s Front Range are related and why they look so different from others of the same species.

“As you learn more, it generates a deeper understanding but also creates more questions,” Estes-Zumpf explained. “It’s hard to ask the right questions when you have a naive understanding. When you understand more you can ask more relevant questions.”

Leaché has continued researching the DNA of lizards in Wyoming and in Colorado’s Front Range. His analysis can answer some of the questions researchers in Wyoming have about the populations in the Cowboy State.

“Dr. Leaché has been studying the genetics of spiny lizards for decades. He’s the perfect person to delve into this little puzzle we have going on,” Estes-Zumpf said.

And so, this ongoing look at lizard populations brought me to the plains in southeastern Wyoming in hopes of capturing a prairie lizard. If we successfully captured one of these lizards, Estes-Zumpf would collect a tail clipping to send to Leaché for analysis.

Still, we had to find them. For hours we walked across the prairie, overturning dried cow pies and debris in search of a lizard. By the early afternoon, the sun started peeking through the clouds. We returned to a promising area and I heard Estes-Zumpf exclaim that she had one in her sights. It took me a couple of attempts with the loop, but we finally had a lizard in hand. It wasn’t a prairie lizard. Instead, it was a Great Plains earless lizard. We released it and continued searching. We spotted another Great Plains earless lizard, then another. By the end of the day, we captured five earless lizards and a prairie racerunner, but the prairie lizards proved elusive. I started to understand even more why researchers want more information about this low-density population of lizards.

Game and Fish technicians continue to collect DNA from these lizards, and they have successfully sent in additional samples for analysis. In time, these captures will help wildlife managers better understand the two distinct lizard species and their populations.

 — Tracie Binkerd is the editor of Wyoming Wildlife magazine.