Coyote Highways

The Story of the Coyote Highways: How winter recreation is changing some of America’s wild landscapes

             

Imagine you are at an office party with nothing but candy for the attendees to eat. Unfortunately for you, you have a food allergy and can only eat blue color M&M’s. Chances are you would defend the blues by asking others to refrain from them, pushing people out of the way of your blue craving, or simply harboring them for yourself. Now, imagine you become distracted just as your cunning coworker slinks her way to the only bowl of M&M’s, and as she does, eats all the blue, green, and red M&M’s. Before you take notice, your whole candy supply – and consequently your only energy source for the night – is decimated. That pesky coworker, for the Canada lynx of the high-mountain west, is a coyote.

Creatures like the Canada Lynx, an endangered feline predator, are perfectly designed for their habitat, which happens to be the high-altitude forests of Wyoming. Lynx are true specialists, almost exclusively hunting the rabbits and hares where they live. In the case of the lynx, it also happens to live in a part of the world with many of its large mammals. Lynx share their shrinking space with mountain lions, wolves, bears (oh my) as well as badgers, hawks, eagles, rodents, deer, elk, and not least of all, coyotes.

In the high mountains of Wyoming, where winter recreation, especially sledding – another name snowmobiling - is a past time for many locals there is an ever-increasing likelihood for human and wildlife interactions. But these interactions needn’t be face to face, and the simple act of passing through makes a difference. With a growing population, and better machines, more of snowmobile rides are being taken each year.

It is hard to imagine how simply moving through on short excursions could radically change the biotic interactions. After all, the snow is surely going to melt, so how can we leave our impact? As it turns out, the sled’s impact is everything. If you’ve ever walked through deep snow, you know how difficult it can be, and similar to humans, animals will choose places where the snow has already been compacted: say, from a snowmobile track. After snowmobilers started noticing coyotes along the track, the researchers from the University of Utah decided to look into it.

The coyote, first introduced to pop-culture as the clever and devious character of the Looney Tunes, is known for being wiley. One of the most sophisticated generalists (an animal with a wide diet) and the only desert-adapted animal to have settled 49 of the 50 states (except Hawaii of course), they often lack the adaptations of native mammals. These adaptations, like the impressively low weight to large foot area, allow animals like the Lynx to glide through the deep, powdery snow. But once a 500lb sled goes screaming through, it compacts the snow beneath it, making areas of easy going for animal movement.

            The researchers wanted to figure out whether the coyotes were randomly coming across the tracks, or seeking them out to travel on them deliberately. They did this by using two kinds of 3-4.5km long paths: first, by drawing random paths across the landscape, and second, by comparing these random paths to the coyotes’ actual path, which they found through animal tracking and GPS collars fitted to the animals.

            What they discovered was fascinating. The coyotes were walking on the snowmobile trails nearly every chance they got. Each of the 57 coyotes walked on a track at some point during the study, spending 35% more of their walking time on the compacted snow of the sled tracks than if they were randomly organized. In other words, over a 5-kilometer path, the coyotes were walking on the track for nearly two of those kilometers. Rather than plunging shoulder deep in the snow, the coyotes naturally gravitate towards this reliable surface, where their small feet stay high in the snow column.

Not only that, but coyotes were encountering prey items much more often on the snowmobile tracks than in the deeper snow. Animals like red squirrels and mice were crossing paths with the coyotes at nearly double the rate they had off the sled tracks. These, incidently, are some of the favorite foods for the lynx of the area. The sled tracks also allowed the coyotes to encounter abandoned deer and elk carcasses from past wolf hunts more often than they would without the tracks.

The coyotes were increasing their usage of the snowmobile tracks as the snow-depth and penetrability, how deep each step plunges into the snow, increased. This physical difference between the snowpack and the sled tracks is just the thing a small-footed canine would want. Not only were the coyotes finding more food, but also they were doing it faster and able to travel further than they had before. This sort of behavioral adaptation allows the coyotes to spend less energy in search for food and mates.

So how does the lynx fit in? These “coyote highways” are being used to access areas of habitat previously reserved only for the lynx. These areas of high-altitude and deep snow made it far to fatiguing for other animals, especially desert-adapted dogs like the coyote, to reach them. With the generalist predator moving in, the food supply of the lynx is threatened, which could spell doom for these already rare cats. It seems that the lynx’s “blue M&M’s” are going to the dogs.

But there is a way to help curb our influence. Naturally, we can’t blame the coyotes for this, they just happen to be smart enough to re-use what we leave behind. The researchers suggested that by rotating the areas that are open to snowmobilers throughout winter season, we may be able to limit just how much we change these especially vulnerable areas of the world. The snow will do the rest, covering old tracks and reducing animal’s ability to invade one another’s space. In this way, we can manage human behavior, rather than following the archaic, often futile, and cruel practice of predator control, where the predators are killed rather than addressing the root of the issue. Killing more coyotes won’t solve the issue, but maintaining an awareness of the trace we leave in these wild places can, for the benefit of lynx and coyote alike.