Cat owners are well familiar with the ability of their feline housemates to get comfortable nearly anywhere: seeking out the tiniest puddles of sunlight, the most cloistered under-the-bed nooks, and certainly any available shoulders and laps.

A housecat seeks out its nap stations based on certain attributes; the same goes for its bigger cousins out in the bush. A study published last November in the journal PeerJ has revealed some of the rather intimate sleeping preferences of one of the bigger members of the cat tribe: the puma (aka mountain lion or cougar).

The insights are only some of the latest to come out of Panthera's Teton Cougar Project, which has also lately explored the scavenger guild that profits from puma kills, the competition (or lack thereof) between pumas and human hunters and the cats' surprisingly rich social lives.

A puma in Grand Teton National Park, part of the Teton Cougar Project's study area (Photo: National Park Service)

For this project, the Panthera team sought out about 600 bedding sites chosen by a number of GPS-collared pumas in its ongoing study, which plays out in the southern Greater Yellowstone Ecosystem (GYE) in the Middle Rocky Mountains of the United States. The researchers cued into these beds using telemetry signals and recognised them on the ground "as a circular depression in the vegetation or snow containing identifiable cougar hair". (The team omitted from its analysis spots where a puma had laid up next to a kill.)

The biologists were curious whether puma bed sites seemed to be chosen for their thermoregulatory potential (warm and cozy, cool and shady), the refuge they offered from competing carnivores, or both. Managing body temperature and avoiding predators (or aggressive competitors) are leading theories explaining any critter's choice of snoozing abode. "Sleeping is among an animal's most vulnerable behavioural states," the authors of the Panthera study note, "and bed sites are an important ecological resource for many species."

Most studies on the sleeping geography of animals have focused on primates and ungulates; the Teton Cougar Project research is among the few to have looked at the topic among carnivores, for which a resting place may serve as a "competition refuge".

You'd think a 45- to 91-kilogram (100- to 200-lb.) cat packing heavy-duty muscle, fangs and meathook claws would be able to sleep just about anywhere it pleases, but in the Rocky Mountain backcountry the puma isn't exactly "top dog" (so to speak). Scavenging grizzly and black bears rout them off their deer, elk and bighorn carcasses, while also posing a threat to kittens. Grey wolves present the same trouble, and sometimes even attempt to kill adult mountain lions. (One on one, a puma may be a match, or more so, for Canis lupus, but a wolf pack is another matter entirely.)

The Panthera team assessed the thermoregulation and predator-avoidance elements of puma beds at two spatial scales: landscape and microsite. At the landscape level, they recorded the habitat type, slope, degree of ruggedness, elevation, aspect (north, south, east or west) and distance to forest edges. The finer-tuned microsite analysis noted the bed's relative concealment, canopy cover and various habitat features.

The results suggest pumas choose their naptime quarters for both thermoregulatory and "predator-avoidance" attributes. In general, your typical puma bed in the southern GYE lies in dense plant cover, on hard slopes, or among/near cliffs and outcrops. Steep and rocky countryside may serve as "escape terrain" for pumas: rugged land amid which they're likely to outpace any wolves that happen upon their hideaway. (Cliff belts also serve as escape terrain for mountain sheep and goats harried by wolves, though the prey doesn't always get away.) Trees offer another refuge for a nimble puma on the run; the cats avoid sacking out in open, exposed country.

In the cold, snowy winters of the study area, pumas often bedded down on south-facing slopes – the warmest aspects, thus fulfilling a thermoregulatory function. But the beds also tended toward steep and lay close to timber: both characteristics reducing a cat's vulnerability to wolves. (In the study area, antagonistic run-ins with pumas and wolves were more common in winter.)

In summer, bed sites seemed somewhat skewed towards the predator-avoidance end of the spectrum, perhaps because this is the season of both especially vulnerable puma kittens and roving bears. But here again, characteristics of summer bed sites can serve multiple purposes: the same heavy cover that hides a resting puma also offers shade on a hot summer day.

Not your typical puma nap zone (Photo: National Park Service)

The Panthera research goes beyond the basic thrill of learning where a big, elusive carnivore such as a puma catches its shuteye. Parsing out the factors that influence a mountain lion's choice for bed sites helps us appreciate the animal's landscape requirements beyond the more obvious geography of hunting grounds.

"When many people think about conserving or managing large predators like pumas, they typically focus on their food requirements (i.e. the availability of prey species like deer)," lead author Anna Kusler wrote in a Panthera blog post summarising the study results. "Though this is definitely an important consideration, pumas must constantly manage a trade-off between finding food and staying safe. Because the best hunting habitats are not necessarily the safest places to sleep, a puma must find a home range that can provide both types of environment."



Top header image: Wade Tregaski/Flickr