We’re getting more of an old-fashioned winter this year. Maybe not an epic winter of old, but it has been colder and more snowy than recent seasons.
That’s generally a good thing as the wildlife of the Northern Rockies evolved to cope with the cold. They may not enjoy winter, but they know how to deal with it.
My favorite critter of the plains – pronghorn – have taken up their usual winter residence along the highway between Powell, Wyo., and nearby Cody. The pronghorn assemble in large herds just south of the highway, lounging in harvested beet fields. Beet greens can be quite tasty; I prefer them with a bit of bacon and onion. Pronghorn seem to think they’re just fine freeze dried.
Those pronghorn don’t hang out in the fields year round. I doubt the farmers would consent to the animals tromping around their growing crops for long. The rest of the year the pronghorn live in the vast plains of sage to the south that reach pretty much to the bottom of the state. Migrations such as this are the pronghorn’s primary method for dealing with winter. To the west of Powell, pronghorn migrate more than 120 miles from Grand Teton National Park to the plains near Pinedale, Wyo. It’s the longest North American mammal migration outside the Arctic.
The trek is necessary for pronghorn as they just can’t cope with deep snow. Each year a handful of pronghorn linger in Grand Teton too long, trying to ride out the winter in the snow. Nearly all of these animals die.
Deep snow makes it tough for pronghorn to find food as the light footed critters can’t dig through the heavy crusted stuff the way elk and cattle can. Pronghorn are also vulnerable to predators when drifts grow deep. Even fawns can easily out run coyotes on the open plains, but the tables are turned in the snow.
Pronghorn also have a problem with fences. Elk can size up a four-strand barbwire fence and instinctively calculate precisely how high to jump so as to just break the top strand as they leap over. But these barriers create something of an existential crisis for pronghorn. The critters are so hard-wired for life on the open plains that they simply can’t comprehend vertical obstruction.
We build better fences in pronghorn country these days. The bottom strand is now usually smooth, and at least 16 inches off the ground. Pronghorn don’t seem to have any problem going under.
When the snow builds up to that bottom wire, even these antelope-friendly fences are impassable. A few years back heavy snows in eastern Montana left pronghorn stranded along the only open country left: roads and train tracks. The resulting carnage included a single Hi-Line freight train that killed 270 pronghorn.
But maybe the worst pronghorn disaster was back in December 1967 in northern Arizona. A truly epic winter storm slammed the region, dropping more than seven feet of snow in Flagstaff. Out on the plains pronghorn were still drifting off the high mesas to winter range. The snow buried fence lines and hundreds — maybe thousands — of pronghorn were found dead in morbid piles stacked along the barbed wire.
The problem for pronghorn isn’t winter, so much as the way we’ve mucked around their habitat with fences and such. But we’ve made great strides. Northern Arizona has become something of a laboratory for pronghorn fence fixes. In addition to the high bottom strands of smooth wire, you also see a lot of goat bars in that country.
Goat bars are lengths of PVC pipe that encase the bottom two strands of a barbed wire fence. The bar lifts the lower strand higher, and the white pipe serves as a visual clue for running pronghorn. The critters barely break stride when they scurry under, at least when the snow isn’t too deep.