Mountain lions were taught to walk on a treadmill at Foothills Wildlife Research Facility to test for energy expenditures. Colorado Parks and Wildlife veterinarian Lisa Wolfe feeds meat snacks to the lions to encourage and reward them. (Paul H. Price)
 
Mountain lions occasionally venture close to town, putting people on alert. Most local residents are unaware that three lions permanently reside west of Fort Collins, but these felines are big pussycats, more adapted to life with humans than life in the wild.

Orphaned as kittens when their mother was killed 11 years ago, the lives of the three were saved by placing them at Foothills Wildlife Research Facility west of Fort Collins, operated by Colorado Parks and Wildlife. At the time, CPW was looking for a way to discover if chronic wasting disease -- usually found in deer and elk -- was transmissible to humans or other mammals.

Lisa Wolfe, terrestrial field veterinarian for CPW, raised the lion trio along with facility manager Tracy Davis. When Wolfe and Davis recently entered the pen area where the lions live, the air was filled with the sound of chirping and soft growling noises as the lions greeted their "parents." As Wolfe approached the fence the communicative noises turned into a loud purr as she rubbed the nuzzling head of Mischief, the female of the group. Mischief's brother, Rascal, was close behind. Spunky, a bit more shy, remained camouflaged under the trees in the fenced-in yard.

The lions are fed twice a week on donated deer and elk carcasses, many that have turned up positive for CWD. Wolfe says there are no apparent signs that the disease transmits to lions, and probably not to people. At 11 years, these lions should be considered elderly, but they eat better than most captive predators. Wolfe explains "they get lots of activity, chew on bones, get organ meat and a good diet," which helps keep their bodies and teeth in shape.

To test their physical and mental condition, Wolfe trained the lions to perform what looks like tricks to the average onlooker, but allows veterinarians to check for coordination, muscle tone and reaction time. With voice commands and a whistle, Mischief stands on two hind legs with her front paws on the cage, allowing Wolfe to get a look at her underside and test her coordination. Another command tells Mischief to extend her paws under the fence opening to have them inspected. Davis opens the cage door between Mischief and Rascal, and Wolfe commands "switch!" -- Mischief and Rascal immediately switch cages.

Mischief leans her front paws against the inside of her cage allowing Colorado Parks and Wildlife veterinarian Lisa Wolfe to assess the lion's physical condition. (Paul H. Price)
 
Training a cat may seem like an overwhelming project to most people. Wolfe says that the hardest part is the initial training, because "once they start learning how to learn they start getting it." They're still cats, however, and "they're only going to do something if they want to do it."

It's not easy for researchers to find mountain lions to learn from, so Wolfe gets attention from scientists across the country. One of the projects involved using special collars fitted with accelerometers that track a lion's use of energy. Conducted by researcher Terrie Williams from University of California Santa Cruz, this project required the lions to learn to walk on treadmills. Williams worked with Wolfe and her staff to create a specially-made treadmill and metabolic chamber.

Wolfe spent months training the lions to feel comfortable walking on the treadmill, enticing them with fresh meat as they strolled along. As Mischief demonstrated her treadmill skills one afternoon, Wolfe suddenly stopped the treadmill motor. "She was starting to get distracted," says Wolfe, "and we don't want this to be a negative experience."

By having both captive and wild lions wear collars, Williams has been able to discover the energetic costs to lions depending on time of day, amount of incline they encounter, and whether they are male, female, or female with kittens. Wolfe adds that it takes a certain amount of energy expenditure for a lion to make a kill, and if it fails to catch its prey, "you can't get those calories back." Wolfe says that some of the young adults who don't do well may just not be good hunters and are expending more calories than the energy they have available. "It took me three years to find someone with mountain lions ... add into that the crazy idea of putting them on a treadmill," Williams says. "Lisa and her facility were fearless, creative and enthusiastic. In the end we accomplished an incredible study."

This research helps with lion-human interactions as well. "Imagine if we could predict when a lion will attack domestic animals or even humans," explains Williams. "We could prevent those kinds of animal-human conflicts making the world a safer place for all."

Each month in Outpost, Deborah Huth Price will write about the studies telling us more about the natural world around us.

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