Fri January 20, 2012
Snow - or a lack thereof - is a perennial January conversation. We put online Doppler radar maps in motion to access a range of snow forecasts. For people, weather news underlies commuting times, power outages and snow sports that drive winter tourism. But for wildlife, winter weather spells survival or death for animals best-adapted to changing conditions.
Which animals win or lose during an open or low-snow winter?
Mammals with varying pelage - snowshoe hares and a diminutive and ferocious native weasel - the "ermine" with snow-white fur and a black-tipped tail - are not particularly well-camouflaged in forests devoid of snow.
Birds and mammals adapted to life under snow include grouse, mice and red squirrels. Snow provides thermal cover and concealment cover for "subnivian" (under snow) species. With little snow, rodents are exposed to predators like owls. Without snow, frost reaches deeper into un-insulated burrows and rain runoff from frozen ground floods burrows, driving mice indoors.
On the positive side, deer and turkeys enjoy easy access to forest "mast" crops including oak acorns, beech nuts and a bumper crop of ash seeds this year. With shallow snow, escape is easy with no wallowing. While predators like coyotes also conserve calories, their advantage while chasing winter-weakened deer is also diminished.
Those of us who hate shoveling roofs and driveways rejoice at a lack of deep snow while ski area operators and snow plow drivers are dismayed. Parallel tales in the woods either punish or profit wildlife based on their specific adaptations and reliance on deep snow for survival.