Tuesday, February 2, 2010

Groundhog Day, Montana Style

February 2nd, Groundhog Day -- halfway between Winter Solstice and the Spring Equinox. For centuries now, it has been a day to remind ourselves that spring really is on its way.

This ancient celebration was born of pagan Celtic cultures, usurped by medieval Catholics, and then hijacked by some rodent-loving, 19th century North Americans. But it's just another day for us working-class rodents here in Montana.

Celtic cultures celebrate the first signs of spring with "Imbolc," (pronounced "im'olk"). This festival is a celebration of hearth and home that includes lighting lots of candles, and looking for omens that hint of fading winter weather. Early Christians liked to recycle pagan celebrations and, after a number of early iterations, "Imbolc" became the Catholic "Candlemas" (or Candle Mass), when priests bless symbolic candles for the faithful masses.

More recently, in 1886, the good-humored German Catholics in Punxsutawney, Pennsylvania, chose this date to solicit a weather forecast from Phil, their favorite groundhog. If Phil sees his shadow on "Groundhog Day," six more weeks of winter ensue. Otherwise expect an early spring, according to Phil's handlers. Phil's handlers also claim that he is one rodent who is more than 100 years old.

Phil's entrepreneurial success has inspired generations of rodents to seek their fortunes as weather prognosticators. In 1956, the semi-famous Canadian groundhog, "Wiarton Willie," started what has been dubbed, "One of the most popular events in Ontario," by adding hockey tournaments to his weather work. Down near Atlanta, "General Beauregard Lee," a wise woodchuck, has received honorary doctorates from both the University of Georgia and Georgia State University for his reported 94% forecasting accuracy rate over a 14 year span. And the Groundhog Day festivities with "Staten Island Chuck" are officiated by none other than the Mayor of New York City -- whom Chuck bit during the 2009 festivities.

Up and coming weather rodents include "Buckeye Chuck" (Ohio), "Balztac Billy" (Alberta), "Sir Walter Wally" (North Carolina) and "Smith Lake Jake" (Alabama).

We're short on groundhogs in western Montana. Instead, we have "Warren Whitefish," "Dayton Dennis" and "Moose City Moses." These three wise guys are hard-working Colombian Ground Squirrels (a second cousin to the groundhog) whose Montana forecasts are always accurate.

You might not have heard of them. That's because in Montana, the duration of winter not in question. When you surface here in early February, you see snow and ice and clouds -- of course -- and there will be at least six more weeks of winter. All of us humans and other animals living here already know the answer to that question.

The better question for those of us living here is, why do our wise Colombian Ground Squirrels (CGSs) start winter hibernation so darned early, in the heat of early August, when there's still so much food left to be eaten?

In the spring, our ground squirrels don't bother sticking their heads above ground until April -- two months after Groundhog Day. Male CGSs appear first, followed by the females a week later. Instead of watching clouds, their preferred behavior is to mate ASAP. There's only a short amount of time to raise young, put on fat layers (and possibly wonder about the weather) when you hibernate for eight months, or about 70% of the year.

CGSs form fairly large colonies, and each squirrel has its own burrow (except for family groups). Young males must leave their home colony and emigrate to nearby colonies, up to 5.3 miles (8.5 km) away, but usually less than 2.5 miles (4 km). The females in each colony are closely related. An adult female with a juvenile daughter will often dig a new burrow, bequeathing the natal burrow to her daughter.

In addition to producing enough progeny to maintain their kind, they must also produce enough fat to carry them through the other eight months. Older males store food in their winter dens to eat in spring -- insurance in case they emerge in snow. They'll eat grasses, dandelions, fruits and bulbs, but the favorite CGS menu item is clover (up to 60%). Dedicated to eating, their summertime body mass will almost double from 12 (340 g) ounces to about 20 ounces, on average, with tubby individuals weighing in at nearly 30 ounces (820 g).

So to survive the long hibernation, a CGS must become rotund. But hefting all that weight around can carry a high price.

Visions of slower, fatter squirrels likely dance through the dreams of coyotes, badgers and hawks -- especially towards mid-summer when they are feeding their own hungry youngsters. Predator avoidance becomes increasingly difficult for a fattening CGS. And lugging those love handles around in the middle of summer also has implications for overheating and thirst management.

Thus, the timing for entering and leaving hibernation gets honed, generation after tubby generation. The availability of food (for producing young and building fat) is continually pitted against summer's increasing predation (slower squirrels and more predators) and heat (heat prostration, thirst).

Over time, the survivors in  this battle have been the late-to-rise, early-to-hibernate Colombian Ground Squirrels. So let Phil and his prognosticating pals hog all the glory and media attention. Montana's ground squirrels are are busy enough just trying to make a living here in the the "Big Sky" state.

Behind the lens: Hard-working Columbian Ground Squirrel photographed in Saint Mary in April. Or was it snowy May?