April 11, 2016


by Steve Lang, Sul Ross News and Publications

woody plants

Price Rumbelow, Sky Stevens, Carolina Medina, Michael Stangl, and Bert Geary with a captured mountain lion in BBNP, (top, photo courtesy of Sky Stevens); Price Rumbelow views mountain lion activity via GPS recordings (bottom left, photo by Steve Lang); captured mountain lion fitted with GPS collar (bottom right, photo by Price Rumbelow).

An estimated one to two dozen mountain lions roam the confines of Big Bend National Park (BBNP), which entertains over 300,000 human visitors annually. On rare occasions, lions and humans meet; even more rarely, with unpleasant results.

Sul Ross State University graduate student Price Rumbelow, Van, TX, is completing an extensive study evaluating the potential for human-mountain lion conflict in the park. Through the use of trail monitors, along with GPS (Global Positioning System) collars on captured lions, Rumbelow’s research seeks to give more information on the times and frequency that lions’ and humans’ paths may cross.

“Mountain lions have not been recently studied in this area,” said Dr. Patricia Moody Harveson, associate professor of Natural Resource Management, who is Rumbelow’s adviser.

“The data we have collected on just their ecology -- both in the Davis Mountains and Big Bend National Park – is important,” she said. “The human impact is an added factor, and Price’s study identifies areas and strategies that could be used to help minimize potential for conflict.”

In the last 10 years, more than 1,000 lion encounters – which range from seeing tracks to actual attacks – have been reported in the park. In the 70-plus-year history of the park, only eight actual attacks have been recorded, none fatal. Encounters are gauged from zero to six, from a sighting of tracks (zero) to a fatal attack (six), Rumbelow said. Anything over a three, defined as contact with property (such as a lion taking food from a campsite or picnic area), is reported as an incident.

“It is fairly unlikely (a visitor) will have any conflict,” Rumbelow said. “And, an encounter can be a good or a bad thing. On the positive side, much of the park is a wilderness area, and there is a chance of seeing a mountain lion in its native habitat.”

Rumbelow said that increased human visitation does raise the odds of lion encounters. “The park offers good habitat for mountain lions, who use the rugged terrain. But there is also a hotel, overnight campsites and primitive campsites that have a high (human) density.”

Rumbelow’s research included placing 20 trail monitors to measure human activity on a seasonal basis (cold months, November-February; dry months, March-June; and wet months, July-October). The monitors shoot lasers from transmitters to receivers. A break in the laser indicates passage, and records the time of day. Trails were measured for two-week periods during each of the designated seasons over the course of a calendar year (November 2014-October 2015). Selected trails in the Chisos Basin, High Chisos (wilderness area), canyons and low desert areas were monitored.

 “The monitors help determine how humans use the trails, when the trails are used, and which trails have the most activity per season,” he said. “This also gives the National Park Service (NPS) great information for monitoring the trail system.” Rumbelow praised the cooperation of the NPS, adding that they contributed six trail monitors for the study.

In addition to the trail monitors, four lions, two males and two females, have been captured -- either with dogs and tranquilizing darts or via barrel traps -- and fitted with satellite/GPS collars. Rumbelow spent several months in BBNP, working with houndsman Nick Smith and technician Bert Geary to capture the lions.

The collars provide 12 daily locations via email, and locations are used to determine the lions’ park use, in terms of areas of highest use at different times of the day. This data is compared with human use to measure areas that overlap and potential conflict.

Rumbelow said the study has shown that lions “used the low areas more than we expected.”

“’Mountain lion’ is a misnomer,” he said. “Lions don’t need mountains, just rugged terrain. When hiking the lower desert trails, (visitors should) keep your eyes open and cameras ready.”

Overall, most human trail use in BBNP occurs in the daytime when mountain lions are less active. Delaying morning hikes until the sun has risen and returning before full dark is likely to lessen odds of an encounter, Rumbelow said.

“I don’t think mountain lions are changing their habits,” he said, “but more visitors can lead to more encounters. Early morning and night time encounters while driving are the most common.”

Rumbelow emphasized that the chance of meeting a mountain lion remains rare. “Cats aren’t confined to areas of high human use. It’s not like every day they are stepping off the trail. With over 800,000 acres (in BBNP), there’s plenty of room for everybody.”

“We have received wonderful cooperation from the NPS and are very excited about the data collected on the lions, as well as the human use of trails,” said Harveson. “The NPS can use this information for seasonal trail monitoring as well.”

“Price has been an exceptional student,” she said. “He has put in so much time and effort into this project and we have learned a lot about the use of the park by mountain lions and people and the spatial and temporal factors where they could overlap.”

For more information, contact, Rumbelow, pricerumbelow@gmail.com or Harveson, pharveson@sulross.edu, or visit our mountain lion research page.