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Extreme temperatures that winter may bring can mean life or death for a lot of species in the north country
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Humans cope with winter in a number of ways, and looking out at the wildlife world it's interesting to compare our mechanisms with those of other creatures and critters.
Take for instance what we commonly call snow birds, or those folks who spend spring, summer and fall in our midst, but choose to winter in other parts of the country where it is warmer and snow is much less likely.
The “snow bird” phenomenon is really not all that different from waterfowl or other bird species that arrive in spring, nest, raise their young and then fly south each year. These long-distance migrations are probably the most familiar examples of how some animals and people endure winter months.
While we tend to associate migration with birds, seasonal movements of mammals also occur, though typically on a less grand scale. In the Northern Plains, pronghorn antelope historically moved up to a few hundred miles to the south or west to escape severe winter conditions.
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Winter migration is common for many animal species outside of waterfowl. Pronghorn antelope may move up to a few hundred miles to avoid winter conditions.
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Nowadays, however, highways and fences can inhibit pronghorn movement. In most years, pronghorns do just fine in their southwestern North Dakota range, but in those years when they need to move, they aren’t always able to get to where the snow isn’t so deep.
A good example is the 1996-97 winter, the most recent year when southwestern North Dakota had much more snow and cold than normal. Some animals were able to migrate out of the worst conditions, but many others perished. North Dakota’s pronghorn population declined by about 75 percent following that winter.
When animals become stressed they need to adapt or move (migrate), or they may die. It’s a pretty simple equation to figure out.
Unfortunately, pheasants are not native to North Dakota and over the years they haven't adapted or changed to better withstand a severe winter on the plains. They may move a mile or two to find heavier winter cover and food, but even that sometimes isn’t enough. It's not uncommon after severe spells of winter weather to find dead pheasants with full gizzards, as sub-zero temperature and wind prove a deadly combination even with ample food supplies.
If you put a pheasant next to a sharp-tailed grouse, one of North Dakota’s native upland game birds, it doesn’t take long to figure out which one is better adapted to survive winter. Sharptails have feathers down their legs and almost out to the toes, while pheasants have no feathers on their legs. Grouse feathers are arranged to better protect and warm their bodies, and grouse nostrils are protected from wind and snow.
And even those adaptations are no guarantee that a grouse will survive winter.
For pheasants, the key to winter survival is heavy, sheltered cover. Even in moderate winters like we’ve had in recent years there are usually spells of extreme cold that can prove fatal. It's a harsh reality that applies to most wildlife. Simply because pronghorn and sharp-tailed grouse are native does not mean they are immune to winter’s challenges. Even in a warmer than normal winter, some animals will die.
When we see wildlife having a hard time, we humans tend to want to help. Providing food for animals is usually the first reaction, but feeding is seldom the answer. The apparent need to artificially feed wildlife is an indication that natural food sources in an area are not adequate. Money and time are almost always better spent on creating natural habitat and food sources so animals can survive on their own over the long haul.
Leier is a biologist with the Game and Fish Dept. He can be reached via email: dleier@nd.gov
