POWELL, Wyo. — Mountain lions, it’s long been thought, are solitary predators that spend their lives avoiding each other.
Not so fast.
Maybe mountain lions aren’t so antisocial after all.
Dr. Mark Elbroch suggested at the Buffalo Bill Center of the West Draper Natural History Museum’s Lunchtime Expedition in Cody on Aug. 7 that mountain lions co-mingle more than once thought.
Elbroch, project leader of Panthera’s Teton Cougar Project, has studied mountain lions for 10 years.
Members of the big cat family seem to avoid one another, mostly.
“Thirty-five of our wild cats are solitary animals,” Elbroch said. The exceptions are African lion prides (social units) and African/Asian cheetahs that establish temporary male coalitions, he said.
Since 2001, 124 lions have been identified and tracked in Panthera’s Wyoming study area, Elbroch said.
The project spans the Gros Ventre Range, Grand Teton National Park, National Elk Refuge and the Teton Wilderness Area in Bridger-Teton National Forest, surrounding the towns of Moose, Moran and Kelly, said Panthera’s website at www.panthera.org/programs/cougar/teton-cougar-project.
Panthera’s findings, supported by GPS radio tracking, suggested mountain lions are not so solitary and even help each other.
GPS collars have revolutionized studies by reporting nearly at real time where the lions are, Elbroch said.
GPS collars track lion movements, identify dens and monitor kittens from an early age, according to the website.
It was thought that mountain lions interact only when the female is in heat or during a territorial dispute, Elbroch said.
Previous research suggested 75 percent of interaction involved male-female courtship, but in the past two years 57 percent of interactions between different lions documented were at a kill made by one of the two lions. Both sexes have shared kills with the opposite sex or the same sex.
“Some food sharing is driving the interactions,” Elbroch said.
Another male dined on three carcasses killed by three females on three nights. He suspects the male was courting the three females or at least checking their breeding status.
Females are in heat between February and late June or early July. Their gestation period is three months, Elbroch said.
In another occurrence, an adult male shared a kill with a starving young male. The sub-adult was at least 40 pounds smaller than the adult, so he didn’t pose any threat.
“They shared meals on a number of occasions,” Elbroch said.
Panthera’s documentation suggested more mutual aid than aggression. In the past few years, Panthera recorded 47 separate encounters involving two mountain lions.
“It’s happening more than we think,” Elbroch said.
Five of those occasions were courtships and 10 more were two lions on the same kill, though the tapes did not record the two predators eating together, Elbroch said.
Panthera has 50,000 videos of many animal types, though most were mountain lions, ranging from one to 18 minutes in length. They want to catalog the videos to share with the public and their scientific colleagues, Elbroch said.
One film taken at night documents a female lying on her back hissing and later reluctantly allowing the lion interloper to feed on the carcass.
“We’re seeing cats as we’ve never seen them before,” Elbroch said.
Drawn together by game, lions likely associate with one another on a regular basis. “Prey availability is driving the overlap in mountain lions,” Elbroch said.
Males, once weaned, disperse a greater distance while weaned females may remain in the same home range as their mother. A male’s home range is 353 square miles and a female’s is 130 square miles. Males located their home ranges to overlap with females and females based their ranges on food availability, Elbroch said.
Mountain lions make their presence known. Scent glands on their feet can be detected by other lions. That is an example of chemical communication, Elbroch said.
Mountain lions do kill each other. In the past two years in his study area there have been two documented killings. In one confrontation, the above mentioned sub-adult male killed a female.
“And he ate her,” Elbroch said.
In the second incident, it appeared a male, new to the area, was attacked by a female with two kittens. The female, may have been protecting her young. She was killed. Panthera is not sure why the female attacked the male, Elbroch said.
Cats kill other cats, but he nonetheless found the two incidents unusual, Elbroch said.
Thus far, Panthera has monitored 124 individual lions, including kittens, documenting their territories, prey selection and population dynamics. Panthera has determined that the approximate 1,426 square mile study area supports an estimated 15 to 20 resident, adult lions, and that population’s numbers have declined significantly in the last seven to eight years. They have learned that lions eat different prey in different seasons, predominantly elk in the winter, with an increasing shift to mule deer in the summer in recent years. “We believe part of the reason for this shift is competition with recolonizing wolves,” said the website.
“Wolves are the dominant competitor for sure,” Elbroch said.
Mountain lions are adjusting their behavior due to wolves and the lion population has declined. Because of that, lion hunter harvest quotas may need to be reassessed, Elbroch said.
Panthera has located about 600 carcasses of animals killed by lions in the past few years, he said.