Winter Arrives to Montana’s Prairie Wildlands
How do plants and animals adapt to the change of seasons on Montana's vast prairie?
Exploring Montana, Featured
Prairie Wildlands Outreach Coordinator
As November rolls around, the snow begins to settle on the Northern Great Plains. The harsh temperatures of the summer convert to a bitter, inescapable cold. Some days the sky might be filled with a wintery greyness and the inklings of snowfall, while others might be consumed with the glowing, low November sun that illuminates the deep fall colors.
Soon, the cattle meandering across the prairie will be replaced with the sound of hunters traversing vast, wild tracts of Bureau of Land Management (BLM) lands. Life on the prairie gradually slows down for the season. But what does happen to life on the prairie as the seasons transition from summer to winter?
Let’s take a look.
Few species are brave enough to stay the winter in Montana’s prairie wildlands. As the days grow shorter, so does the number of birds. The suite of birds that inhabit the prairie during the summer is whittled down to just ten or so species. Those that do stay often have rather creative methods for filling their bellies given that food is typically more difficult to find during winter. For example, the sly Northern Harrier uses its acute sense of hearing to hone in on the unsuspecting prairie or sagebrush vole as they scurry around their vole holes under the snow.
As our Clark’s nutcracker friends to the west begin their seasonal harvest of whitebark pine seeds, the northern flicker stows away the seeds and berries of many plants that can be found on the grasslands. At night, the birds that brave the cold here stay warm by packing on the ounces, fluffing up their feathers like a pillow, and slowing their heartbeat.
As winter dawns on the mammals of the prairie, there are only a few that pack up their bags, most notably the pronghorn. The pronghorn migration is one of the longest and most intense mammalian migrations in the world. They rely heavily on open, wild lands to make their way to the grasslands of our neighbors to the north. They can run up to 60 mph and will travel several hundred miles quite easily.
After the fall rut, elk begin expanding their diet from grasses and flowers to grasses, shrubs, and trees. Typically, elk enjoy the views from the higher elevations during the spring and vacation in the lowlands during winter to avoid snow. Can you blame them? I too would prefer not to dig through snow to get to an already cold dinner.
The black-tailed prairie dog is difficult to find during winter on the prairie. However, it’s not because they aren’t there. When the temperatures drop too far, they return to their underground homes, shut the dirt door, and go into torpor. When these little critters go into torpor their bodies are just a few degrees above freezing. They remain safe and warm enough in their burrows regardless of conditions outside.
The dry crunch of cured grasses slowly turns into the crunch of frost wrapped around the shoots. Some grasses are like frogs when winter begins. Sounds crazy, I know, but the presence of glycerol (a form of sugar) in the frog's body increases in the winter, acting like anti-freeze in their blood. Similarly, some grasses endure cold weather by creating more sugars through photosynthesis.
Our state grass, bluebunch wheatgrass, can be found all across the prairie wildlands of Montana. Like most grasses, bluebunch wheatgrass sends nutrients underground to its root system until spring. I’ve had plenty of time to study them because the city of Billings has planted bluebunch wheatgrass on our roundabouts!
The Great Plains and narrow-leafed cottonwoods that often trace the riverine systems throughout the prairie eventually turn from green to bright yellow. Like migrating birds, this reaction is triggered not by temperature, but by sunlight. As the days become shorter, its leaves produce less chlorophyll (which makes leaves green) and eventually the carotenoids (yellow and orange pigment) overtake the leaf. The leaves eventually fall when the veins of the branches close up and seal the nutrients inside of the tree. This process ultimately leads to yard work, allergies, and pumpkin-printed trash bags full of leaves near Halloween.
What happens to our families on the prairie this time of year? For a few, it means long hours of harvest, to others it means warm scarves and hats. Farming and ranching families often begin their work early when it’s cold and finish late when it’s still cold. For some, fall does not technically begin with the autumnal equinox but rather the date that Starbucks begins selling pumpkin spice lattes. And yet for others, autumn on the prairie means the inauguration of Henry David Thoreau-esque “saunters” across golden parcels of prairie wilderness. While these landscapes might at first appear bland and uninteresting, autumn reminds us that the prairie is a macrocosm.