Desert Notes: Mountain Lion Refugia

Story and Photos by Robin Patten

Morning coolness lingered in the side canyon, the heat of summer yet to reach into the depths. I walked the dry wash along the canyon bottom, watching the cliffs for the wrens chittering somewhere above, looking down only to secure my way – and so the mule deer head startled me, lying in my path, upside down below a cottonwood tree. The head was intact, no rot, no flies, eyes closed, big ears soft with veins still showing. The delicate whiskers on the small jaw somehow made the young doe appear like a character in a children’s story, innocent and sweet, a contrast to the exposed bloody red neck vertebrae extending from the head.

A mountain lion kill. Most likely from the night before. Only a few coyote tracks pitted the sand nearby. I presumed the remainder of the carcass was further up the canyon, the head dragged down by the coyote.

A week before, I’d walked up Cottonwood Wash east of that side canyon, to find mountain lion tracks patterning a stretch of trail, unmistakable cat prints with a lobed pad and roundish toes. The lion had walked up the canyon, then down the canyon, up and down a few more times, the tracks both under and on bike and boot prints. A few days later, rain had wiped the trail clean of prints; there was no sign of a lion in Cottonwood Wash – then the deer head appeared in the side canyon a few kilometers away. The same cat? Or a pair, an overlap of female’s territory within a larger male territory?

It was not long after finding the deer head that I ran across mountain lion tracks in the main canyon below the kill, confirming the cause of the deer’s demise.

Mule deer are the mainstay of mountain lion diets. As an obligate carnivore and an opportunist, mountain lions will prey on many other species, including everything from rodents and black-tailed jackrabbits to porcupines, but deer are a prime target. In Utah, mule deer make up over 80% of mountain lions’ diet, meaning good habitat includes a substantial ungulate population. Cover to conceal stalking adds to habitat quality. Put these factors together and the preferred habitat in Utah, according to Utah Division of Wildlife Resources[1], is pinyon-juniper and pine-oak brush areas, especially places with ledges and cliffs. Females with young favor areas with the sheltering protection of large conifers and dense shrub.

The rough country around Bluff has its ledges and cliffs, but a paucity of trees, and certainly no pinyon-juniper woodland. Yet here they are, mountain lions, seemingly a constant presence, not just passing through.

I started seeing mountain lion tracks my first winter in Bluff, in the snow by the San Juan River a few days before solstice. The lion had walked along the riverbank, then into the willows where its trail disappeared. The next day, more tracks in snow showed a mountain lion had been east of Cottonwood Wash miles above the river. The day after that, I found fresh prints west of the Wash, this time in the dirt.

Of course the snow helped, though I wondered if I’d picked up a search image, that I was just beginning to actually see the prints. Yet there was an enigmatic quality to these sightings, numerous tracks so close in time yet spread so far in space, the trace of a large hunter, a creature who usually seeks its prey when light is rare, most active at dusk and dawn. Secretive and elusive, seldom seen, mountain lions are both a wonder and a mystery in their presence. They are also a top predator and so can be an integral part of a healthy ecosystem.

Mountain lions historically ranged across the United States before they were eradicated from the eastern regions. By taking advantage of western North America’s rugged terrain, the cat managed to persist in western states, occupying a diversity of habitats. As those lion tracks in snow and sand demonstrated, this includes remote arid regions of Utah.

Southeastern Utah’s high desert is not prime habitat; it is an environment where mountain lions require larger territories to survive – there is simply less prey available. These areas can also be difficult for humans to access. With low lion population density and an environment not amenable to hunting – especially by hounds – hunters tend to go elsewhere and human pressure is less. This means that, as a University of Utah research project[2] found, survival rates in these lower quality habitats might actually be higher than in the core population areas where human pressure and anthropogenic mortality are greater. Utah’s remote arid lands are thus a refugia for the big cat, a significant fact for mountain lion conservation.

The researchers concluded that southeast Utah’s marginal habitats may have “greater conservation value than has been previously assumed” due to a source-sink dynamic. Because these environments require larger territories, they have lower carrying capacity; subadult mountain lions must disperse outward. These arid lands are thus “net exporters” of lions – a source – even though the population density is relatively low. Provided corridors and connectivity exist across the landscape, the dispersers move into the core prime habitat, the sink areas. This source-sink dynamic can help maintain the lion population in the core areas where human-caused death rates are higher. This gives a new perspective to those mountain lion tracks encountered in this high desert region.

Weeks of wandering the Bluff surrounds can pass without any sign, and then it seems a lion or two is around, tracks appearing in one canyon and then another. Still, the animal itself eludes me, and I’ve not caught sight of the cat, something I’m quite happy with. To find a paw print in the dust is enough, just to know the big predator is here. To find the remains of the hunter’s kill elicits a response beyond that. A respectful pause.

In that side canyon, standing with a deer head at my feet, the lion’s presence felt tangible. There was no wind, no leaves rustling, no water trickling. It was desert quiet, a deep silence broken by a lone bird call, bee buzz, again silence – a potent silence holding a sense of anticipation, as if something waited. Within that quiet was a mountain lion, residing in this land that is a refugia for the big cat. And most likely many other beings.

I did not venture further. Not my place at that time.  

[1] Pederson, J. “Mountain Lion (Felis concolor)”. Wildlife Notebook Series No. 5, Utah Division of Wildlife Resources.

[2] Stoner, D. C., Wolfe, M. L., Rieth, W. R., Bunnell, K. D., Durham, S. L., & Stoner, L. L. (2013). De facto refugia, ecological traps and the biogeography of anthropogenic cougar mortality in Utah. Diversity & distributions, 19(9), 1114-1124.