A changing ecosystem: on wildlife small and large

Coming back to my cabin after months away always evokes feels that old John Denver song, Back Home Again. Things seem pretty much the same as I remember from last year, and then I start to notice the differences. There’s always the weather, some years being wetter, others drier, and the result is more or fewer worries about fire. This year Linda and I have been talking about how the eco-system is decidedly different from other years. Top changes are the disappearance of ground squirrels, the fewer numbers of hummingbirds and the proliferation of an animal that rivals humans for domination of the planet: ants.

Below is a photo of a ground squirrel, taken a couple of years ago. Ground squirrels live in burrows underground, sleeping for most of the year. By the time I would arrive in the early summer, the young ones were out of the nest, gamboling in my compost pile and chasing each other through the yard. At one point I worried that they would reproduce in such numbers that my backyard would start to look like those 19th century photos of the American West, the ones showing thousands—no, millions—of prairie dog burrows along train tracks. But the population never exploded, as predators kept the balance. Still, I always had mixed feelings about the ground squirrels living next door to me—enjoyment of their playful antics and annoyance that outdoor gardening was impossible.

Those critters are nowhere to be seen this year, and it’s pretty clear there are two reasons for that: evidence (large holes) of one or more badgers during the winter and the appearance last fall of a family of feral cats. Mercifully, the 3 cats are all male, one the father (presumably) and the other grown kittens. How do you know they're all male? I asked Linda, picturing a future “prairie dog village” of felines. “I know,” Linda replied. “I felt their balls.” Reassured by her confident assertion, I began to appreciate them more. They are actually semi-domesticated, and they have names. Linda, who loves this little family, built a hay fort for them to get them through the winter and supplemented their hunters’ diet with cat food. One of the grown kittens, Buttons, likes to be petted, and all three can be seen napping in the shade on Linda’s doorstep during the afternoon. Here is a photo of Babe, the other grown kitten, looking, well, quasi-feral.

Yet, even with these three, it’s clear how the introduction of a predator species can alter the wildlife landscape. The wild rabbits are gone, hopefully safe and nesting in a neighbor’s woodpile; so are the mice (no regrets there, I confess). There also seem to be fewer flies. Is there a connection in that fewer rodents means fewer insects/fleas for flies? Is there a connection with the drop in the number of hummingbirds, who, contrary to popular belief, rely on airborne insects for food as well as on the nectar I still faithfully put out. At the same time, a male broadtail I call “bully bird” has been guarding my feeder, chasing away others except for one female, presumably his. Perhaps something else is going on in the hummingbird world, something we don’t see. Or, as it’s a dry year with fewer wildflowers than usual, the birds could have found a more hospitable micro-climate. With complicated ecosystems, all we can do is speculate.

Then there are the ants. Plenty outside and sometimes they bite. Not too many inside, but enough to bring out my murderous instincts: too close to my kitchen counter? Swat! Hoping to balance out my ants-as-pestilence attitude, I checked out a DVD of a PBS special on E.O. Wilson, the renowned biologist who dedicated much of his life to studying ants. There are 16,000 species of them in the world—which I find astonishing—and that’s just the number that have been discovered. Professor Wilson, now Emeritus, contends that if you put the weight of all of the ants in the world on one scale and the weight of all humans on the other, the weights would be roughly equal. I confess that didn’t curb my swatting instincts. Since our species seems well on the way to promoting our own extinction, I find myself mumbling to them, “You’ll have the earth soon enough!) Wilson says people often ask him what to do about ant invasions. “I tell them to crumble a cookie on the counter and then watch their behavior,” he advises. Clearly it’s better to ask a scientist about curiosity, not extermination. As for me, most days I just focus on not dribbling hummingbird nectar on the floor, cleaning counters and hoping for the best.

In the years I’ve been coming to stay here for stretches of time, my sightings of larger wildlife have been astonishingly few. A small herd of pronghorn crossing the land at a distance, a discreet coyote near the dry stream bed at dusk, an occasional deer jumping the fence across the road, a few wild turkeys. Neighbors with forested land or rocky outcroppings can usually add bears and occasionally, a mountain lion, but here, on this open former pastureland, they would never pass during daylight. Include the semi-wild mammals, and I can add visiting herds of donkeys that stayed for a day or a few before heading out the always-open gate. Then there are the domesticated llamas, cows and horses seen along the road from time to time.

I miss the donkeys. As a species, they’re the descendants of pack animals used during Colorado’s mining days. They’re legally protected in Colorado, and often something of a tourist attraction. Cripple Creek, a neighboring town, boasts a resident herd and a summer donkey race event. “Our” donkeys stopped coming a couple of years ago after the rancher who supposedly owns them built a better fence (or so we heard), stopping their wanderings in the neighborhood.

I suppose scarcity breeds appreciation. This morning, while walking with Linda and her two dogs through the trees across the road, we spotted a deer, a beautiful young buck, wandering freely through the trees. A beautiful moment it was in a changing and dynamic ecosystem. And as we reached the road, we looked over at the haze above distant mountains. Smoke from wildfires in Utah and Arizona,   where ecosystems will undergo major changes this summer. We're grateful to be spared--today.