This blog post is excerpted from Into the Night: Tales of Nocturnal Wildlife Expeditions.
Most mammals are nocturnal, and this certainly goes for the charismatic megapredators that intrigue so many people. Throughout the Rockies, large-bodied predators such as black bears and mountain lions prowl the night shadows. For the bears, an omnivorous diet consisting mostly of vegetable matter makes up the menu. Mountain lions, however, adhere strictly to the Atkins Diet, eating very little besides meat, which they acquire by ambushing their prey (usually deer), and darkness provides perfect cover for such a hunting strategy. The victims likely never see their attacker; the strike comes from above and behind with no warning, crushing the back of the skull.
My encounters with mountain lions have been many and varied. In some cases, individuals have sounded their presence by screaming a territorial plea apparently meant to move us out of their province. In most cases, if the plea goes unheeded, the lion gives up its demand and moves away. However, in one particular case, a test of wills ensued.
It is July 1999. Krista, a graduate student, and I are netting bats at a small water hole in the ponderosa pine woodlands of the Rockies. On the hike in, Krista expresses how much she would love to see a “big cat” this summer. Aloud, I tell Krista that sightings happen occasionally. My unspoken response is: Be careful what you wish for.
As darkness approaches and the bats begin to fly, a familiar and unsettling sound is aired, as if conjured by Krista’s wish. It is indeed a cougar, and it is screaming at us to leave the area. I tell Krista not to be alarmed, that it will most likely give up and move off. However, instead of retreating, the screams persist, and the cat seems to move closer over the next thirty minutes. The nearer the cat comes, the more desperate its cries become. Forty minutes pass and the only change is the level of vocal desperation coming from the cougar, now including deeply guttural and mournful moans and groans. I seriously consider leaving the area, which would be a first for me. Krista and I stand in silence. I shine my headlamp in a 360-degree circle to try to spot the beast. In an instant, the lion’s eyes appear from atop a rock on the adjacent slope, a mere one hundred feet away. The cat peers intently, blinking momentarily as it moves from its perch in our direction. I begin to panic somewhat, but not in a way that Krista would notice, and I tell her in a calm voice that we should pack up and leave. We break down the net, nervously and hastily cramming the gear into our backpacks with little care. As I rise from bended knee, my headlamp strikes yellow eyes shining back at me, now from twenty feet away. I can see the entire animal. The cougar’s ears are pinned back and its stance is erect and rigid, a clear threat display. I reach down and scrabble the ground for a small rock, which I toss elliptically to the side of, but near, the cat. The cat averts its gaze from us, looking in the direction of where the rock hit the ground. As it is momentarily distracted, we move quickly, hiking down and away in silence, our actions apparently appeasing the cat, as we hear no other sounds from it as we scurry away.
As we descend, I begin to wonder why this event happened. What was it about our presence that stimulated the persistent demands for our departure? Was the cougar trying to access water? Probably not. There are many areas along that steam where a cat could drink. Were we near a cached kill and was the cougar was coming back to feed? Possibly. Cougars cache large prey (a deer, for example) and revisit the carcass to eat for days.
The next day, I discussed our adventure with the local rangers, and two of them hiked to the site to determine if a cache was indeed present. None was found (however, such caches it can be difficult to find). Another explanation for the encounter might be related to reproduction. From this individual’s size and slender appearance, it appeared to be female. Perhaps it had young kits nearby and saw us as a threat to their safety. Whatever the case, a lesson in persistence was learned—by us and by the cat—this night.
Although that was the first and only time a cougar actually approached with the intent to move me from an area, other encounters with these large cats have been equally unnerving. One was years earlier. Kate, a student from Boston College, is working with me on the ecology and behavior of the nine common bat species distributed through the eastern foothills of Colorado. On this occasion, Kate and I are catching bats at a small pool of water that forms as a trickling stream crosses a footpath. The footpath makes an easy access “route” for flying bats to descend and skim the surface of the pool to drink from a cool mountain stream. We string mist nets across small water sources like this because bats concentrate around them and they are not expecting our nets. Otherwise it is almost impossible to catch bats in free flight; they are simply too fast and maneuverable. Tonight, a full moon greets us and at once highlights the landscape’s rugged beauty while exposing mysterious shadows and ghostly shapes that evade focus, blending imagination and certainty. “Business” is slow as it is a rather cool night and our winged friends apparently are not seeking a cool drink at the stream. In silence and half asleep, Kate and I sit on the ground next to our nets, waiting patiently. We know this is not going to be a record night for numbers of captures, but it is sometimes on slow nights like these that a rare species, such as an eastern red bat or even a Mexican free-tailed bat, shows up.
As I gaze, half alert, into the darkness at the opposite edge of the small pool, I notice a slight blur of motion that breaks the edge of shadow and moonlight. For some reason my brain signals that something is amiss. I am in mid-thought when Kate whispers, with equal hesitation and concern, “What was that?” I immediately trigger my head torch, only to be astonished at what stands before us. A mere six feet away (remember, we are sitting on the ground) are two fully grown mountain lions, and we suddenly find ourselves literally face-to-face with the region’s apex predator, which can weigh 165 pounds and is known to have a pouncing distance of thirty feet. We are sitting ducks. As the light from my headlamp hits them, fortunately the cats are momentarily confused, stretching their necks as if trying to peer through a sudden and unexpected sun.
A moment later, I find myself standing and instinctively yelling while breaking into some sort of primal dance, throwing rocks and sticks in an attempt to intimidate the predators. Kate is also standing, but stunned and motionless. My dog, Jasper, a husky-golden mixture, is sitting in his usual calm state, watching all this with restrained curiosity, almost amusement. The cougars respond to my actions by backing off about ten feet, but hold their ground. I yell louder and more emphatically. I shout at Kate to hand me rocks. It would not be wise for both of us to bend down. I throw several large rocks, not really trying to hit the cats, only hoping to scare them off. Eventually the larger of the two takes off down the trail, apparently having had enough of our antics. The smaller lion, however, cannot still its curiosity and begins to crouch and move behind the vegetation in a circling pattern. I continue to throw rocks and sticks, but the situation lacks improvement. My adrenalin peaks. I reach down and grab a baseball-sized rock. Winding up like Sandy Koufax, I hurl my best fastball. It meets its mark, pasting the remaining lion on its side. The cat lets loose a resounding groan and runs down the trail after its buddy. I release a primeval scream from depths previously unknown to me. Kate and I breathe sighs of relief and decide to pull out the nets and leave the site.
As we descend the trail with a forty-five-minute hike ahead of us to civilization, my mind begins to wander into thoughts of deep time, the long distant past when our species—and, before them, other hominids—were commonly faced with threats similar to and surely more terrifying than this one. Then the stakes were much higher. Prowling carnivores were more diverse, and many were gigantic by today’s standards. For example, in North America, scimitar cats the size of African lions stalked the night, as did two species of saber-toothed cats, the largest of which, Smilodon, weighed up to 650 pounds. The short-faced bear, which dwarfed today’s grizzly bears, roamed at will. An American cheetah, Miracinonyx, coevolved in North America with pronghorn antelope, thereby selecting for their high-speed running ability, which far outpaced any current predators on the range. There were, of course, mammoths and mastodons and bison that were six feet at the shoulder and weighed more than 2,000 pounds. Even beavers reached gigantic sizes of 600 pounds or more.
Those were, indeed, different times, and my thoughts of them brought our encounter with the curious cougars into perspective. Past humans had to contend with daily threats beyond our imagination, and they did not have a house or car to retreat to. It is humbling to think about the path of human evolution compared to the sterile surroundings many people prefer today, living an existence almost entirely separate from, and fearful of, nature. I never have felt more alive than I did just after this incident, an obvious side effect of adrenalin. The cats, likely young siblings that had recently left their mother, clearly were curious rather than aggressive. Otherwise they would have pounced on us before we even knew they were there.
Rick A. Adams is a professor in the Department of Biological Sciences at the University of Northern Colorado and founder and president of the Colorado Bat Society. He is the author of Bats of the Rocky Mountain West: Natural History, Ecology, and Conservation and Into the Night: Tales of Nocturnal Wildlife Expeditions.