August 21, 2014

Collaring, literally, mountain lions

by Lonn Taylor

milaniDana Milani of Alpine walks up to mountain lions and puts radio collars around their necks. The lions are tranquilized, but in my opinion it is a scary job. Milani loves it. She is a trim woman in her 40s who looks like an Olympic swimmer. She has been an Outward Bound instructor and a river guide and is perfectly at home in the outdoors. She takes collaring mountain lions for the Borderlands Research Institute in her stride.

Milani is one of a half dozen technicians who are helping Dr. Louis Harveson and his colleagues at the Sul Ross Borderlands Research Institute learn more about mountain lions. “They are extremely elusive animals,” Harveson told me, “and there is a lot we need to know about them if we want to understand how they use the environment of the Big Bend. For example, we’d like to know more about what they eat, and how far they range, and how their habits affect the other animals they share the environment with. The first step in doing this is to be able to track their movements and examine their kill sites.”  The collars that Milani and her colleagues put on the lions contain a GPS transmitter that sends a signal every three hours, which enables the Sul Ross researchers to track their movements. Mountain lions travel astonishingly long distances in search of prey, Harveson says. A male lion’s range in the Davis Mountains might cover 130 square miles, a female’s, 80. A young adult male striking out on his own may walk 400 or 500 miles to establish his own range. Harveson told me about a lion that was trapped and collared in South Dakota and killed by a train in Oklahoma.

Milani and another technician, Bert Geary of Fort Davis, told me how they put the collars on lions. First, they set a string of Aldrich snares, traps which are activated when the lion steps on a small steel plate, releasing a steel cable that grips the animal’s foreleg but does not puncture the flesh. “We check the snares every morning, and if we have a lion we immediately call for a backup. I would never work on a lion alone,” Milani said. Geary said they get one lion about every 45 days. “You’ll catch the lion as soon as you’ve given up hope,’ he explained. Once the backup arrives, the technicians tranquilize the lion by shooting a sedative-filled dart into its flank from an air rifle. “It takes the lion 15 or 20 minutes to go to sleep,” Milani said. “Once they are out, I walk up to them and tug an ear, just to make sure they are asleep. Then I go to work.”

The technicians take the lion’s temperature with a rectal thermometer, extract a blood sample, and estimate its age by opening its mouth and measuring its teeth from the gum line to the sharp end. They put an ear tag on the lion, photograph it, and finally put the radio collar around its neck. All of this takes about half an hour. Then they give the lion another shot, which will wake it up, release its leg from the snare, and stand back. Geary remembers a lion that woke up while Geary was working on him. “I think the sedative might have been out of date,” he said. “The lion jumped up. One person grabbed him by the tail, another got a catchpole around his neck, a third was trying to get the snare. We looked like the Keystone Cops. It took three injections to get him back to sleep.”

In the wintertime, when the weather is cool, the technicians sometimes work with a professional lion hunter who uses dogs to tree the lion, rather than catching it in a snare. Once the lion is treed, the procedure is the same: it is tranquilized, collared, and released back into the wild. But the chase can be exhausting. Geary recalls one hunt with Nick Smith, a hunter from Quemado, New Mexico, and half a dozen dogs that covered six miles of mountain slopes before the lion was finally tranquilized. The lion went up and down three trees, and at one point Geary was close enough to it to touch it. “Grab him by the tail,” Smith shouted to him, “and if he turns around just pull back!”

Examining kill sites is not as exciting as catching lions, but it is an equally important part of the project. Harveson says kill sites are located by charting places lions have returned to over several days, or have remained at for several hours at a time, and are often confirmed by circling buzzards. He and the project assistants have examined 164 kill sites so far. From the remains they have found they have determined that the main dish on a mountain lion’s menu is deer, followed by generous helpings of feral hog, javelina, aoudad, and elk, and dashes of coyote, skunk, fox, porcupine, and coati. They have found no evidence of lions killing livestock. Livestock predation was the reason Big Bend ranchers in the last century hired lion hunters, and efforts were made to extirpate the mountain lion on the grounds that they were a threat to ranchers’ livelihoods.  “There are fewer livestock here than there used to be,” Harveson told me, “and people take better care of their cows and calves. No one in the Davis Mountains is raising sheep or goats anymore, and they were certainly prey to lions.” Harveson is aware than anything to do with mountain lions can be controversial. He points out that the mountain lion research project started five years ago when ranchers went to the Borderlands Research Institute asking for information. “Our job is science,” he told me. “We gather the data and we present it to landowners who are both pro- and anti-lion.”

Harveson knows as much about mountain lions as anyone in Texas. He wrote his dissertation at Texas A&M on them, and while he was doing his research he trapped and collared 22 of them along the Nueces River. When I asked him what he would like people to know about mountain lions, he said, “That they deserve our respect. They are trying to carve a living for themselves out of this rough, inhospitable country and they are largely successful at it. They are remarkable animals.”

Lonn Taylor is a historian and writer who lives in Fort Davis, Texas.