Tracking Mountain Lions In Texas: Study Suggests Population Is Stable

Price Rumbelow
By Lorne Matalon
October 30, 2014
Audio Clip

Tracking Mountain Lions In Texas: Study Suggests Population Is Stable

This Texas mountain lion died after stepping into a metal snare laid down by a ranch owner who wants to eliminate mountain lions. Some ranch owners maintain that lions should not be studied but be killed. This image was taken October 18, 2014 in Brewster County, Texas by a trapper employed by the ranch owner. The trapper did not wish to be identified.

The mountain lion of Texas is known by many names in the Southwest. Cougars, panthers and pumas to name three.

In California it’s protected. In Arizona and New Mexico, you can hunt this predator, but with strict limitations. In Texas, mountain lions can be hunted at will. Still, preliminary results from a four-year-old study suggest that the Texas mountain lion population is stable and may be growing.

Data from a Texas project tracking mountain lions by satellite imply a population of between 25-40 animals in one of the sky islands in Texas. Sky island refers to a mountain range surrounded by flatlands or in the case of this study, the high desert that's a 90-minute drive north of the U.S.-Mexico border.The project, privately funded by individuals and nonprofit foundations, is an initiative of the Borderlands Research Institute (BRI) at Sul Ross State University in Alpine, Texas.

What separates this project is that it takes place on private land, an accomplishment in a state where 95 percent of the land is in private hands. What’s more, most of the test area is owned by ranchers, many of whom have harbored revulsion for the mountain lion.

“You have to understand the values that people have, the history that they (ranchers) have, the culture that they have," said Louis Harveson, the leader of the research team.

That history is marked by a loathing for the animal, the notion that mountain lions should be killed on sight. Yet Harveson’s managed to get more than 50 ranchers and other landowners to open their gates to his research team. Harveson assured ranchers that no lions would be brought in from other regions, only that the existing population in the Davis Mountains of west Texas would be studied. He also asked ranchers to consider the animal’s role in maintaining nature’s checks and balances.

“Mountain lions are the apex predator, just like sharks and oceans," said Harveson.

"There’s a food chain that’s in existence," he explained. "And that apex predator symbolizes wildness. This animal that’s able to kill a deer a week or a large prey item a week, that just says that there’s a good healthy ecosystem intact.”  

In four years, Harveson’s team has used leg snares to capture 22 mountain lions, tranquilize them and place satellite and VHF radio beacons on their collars.

James King is a landowner whose family has deep roots in ranching. He’s allowed the research team on his land to record details of the animals’ diet.

“The kill sites are detectable by the fact that the lions don’t move with these GPS collars," said King, referring to the GPS location beacons. When the signal remains fixed on a location, it means one of two scenarios are unfolding.

Either the animal has died, or the stationary signal suggests that the lion has stopped at a kill site, a place where the animal eats its prey.

Wildlife biologist Dana Milani is a member of the research team. She crosses canyons and sepia-toned mountain ridges every working day. She documents the lions’ appetite for deer, rabbit and porcupine. That appetite keeps those lower-level species in check.

“You’re always trying to be quiet to stress the animal less," she said while moving through underbrush.

Patricia Moody Harveson
A female adult wakes up after the sedation wears off. She's outfitted with satellite and VHF tracking beacons on her collar.

She said she has been fortunate lately given how elusive the mountain lion is. Milani recently checked and helped collar two adults, a female and a male. She took samples of blood and tissue for genetic analysis before withdrawing and letting the sedation wear off.

She said without the support of ranchers and other landowners, she could not paint a picture of how lions sometimes help ranchers.

A case-in-point, James King has trouble eliminating feral hogs. That’s an invasive species brought to the Americas by Christopher Columbus.

“I shoot a lot of feral hogs and they’re hard to exterminate. And those lions are out there at night doing that job," he said with a wide smile.

King said the antipathy toward the mountain lion goes back to the days when sheep and goats were raised in this part of the Southwest. Today, King said, ranchers principally raise cattle. He said he's encouraged by one development profiled in the study.

courtesy: Borderlands Research Institute
This image shows the Davis Mountains in far west Texas. Home ranges of adult female mountain lions are traced in yellow, red, and green and a male's home range is in blue.

"Here in the Davis Mountains, we’re not seeing any kills of domestic cattle," he said.  

"We’ve documented over 200 different kills," said project leader Harveson. "And not one domestic animal has fallen to mountain lions and that’s a fact.”

Across the Southwest, attitudes toward the predator may be changing.

Private landowners in Arizona have just agreed that a 10-mile corridor traveled by lions will be protected. In California, a new UC Davis study suggests migration corridors be created to avoid lions being hit on the highway.

James King said he’s not an evangelist for mountain lions. But like many of his neighbors, King simply wants information about the animal.

“Let’s give these scientists access so they can help us understand the movement, the population, their whole dynamics so we can be better land managers," King said.

The leaders of the Texas study said they don’t want to influence policy. They just want to gather data so that policymakers and area ranchers can make informed decisions on mountain lion management.