By Jack Souther, Whistler Naturalists
The April sun had all but wiped out the Blackcomb Glacier road. What remained of the snow was black with dirt sloughed from exposed banks and meltwater puddles filled the ditch. Definitely the end of the ski season!
Threading my way through the rocks I was startled to see what I took to be just another pebble dart across the trail and up the bank. A panic-stricken vole, flooded out of its nest by a spring freshet, was desperately searching for cover. As I watched the tiny creature cowering under a root I was reminded of that other "wee tim'rous bestie" that inspired Robby Burns to write, "The best-laid schemes o' mice an' men..."
Though often referred to as "field mice" voles belong to a separate subfamily (Microtinae) that includes the lemmings and muskrats. Unlike true mice, with their sharp muzzles and long naked tails, voles have short stubby tails, blunt muzzles, and moderately long hair that almost covers both their ears and feet. Their tiny bodies, weighing between 1 and 2 ounces, are short and compact.
The vole that I met on the Blackcomb Glacier road was probably a western red-backed (Clethrionomys californicus), a species that commonly inhabits the West Coast rain forest. Like other voles it does not hibernate but spends the winter actively foraging for grasses, seeds, roots and fungi. Much of its time is spent under the snowpack where it builds a round nest of shredded grasses about the size of a softball. This is connected to an extensive labyrinth of burrows running under and through the snow.
Despite its small size the hapless vole is just about every carnivore's favorite snack. Few live more than a few months. Hunted in its burrows by weasels and pine marten, picked off by opportunistic coyotes and bobcats, and snatched up by waiting owls, their very survival seems miraculous. The answer lies in their prodigious rate of reproduction which eclipses even the legendary fecundity of rabbits.
Voles continue to breed throughout the year, producing new litters even when their nests are covered by winter snow. Females mature at the age of three weeks; pregnancy is less than three weeks and new mothers may become pregnant immediately after giving birth. In his book, "Mammals of the Canadian Wild," Adrian Forsyth recounts the astonishing feat of a well-fed captive vole that gave birth to 17 consecutive litters, producing 83 offspring and 78 grandchildren before reaching her first birthday.
Striving to survive in a fragile burrow under the snow at the very bottom of the food chain about the only sure thing in the short, harried life of a vole is the absolute certainty that schemes will indeed "...Gang aft a-gley".
Upcoming Events :
May 5 Monthly Bird Walk. Meet at the base of Lorimer Road at 7 a.m. (please note earlier time). Contact Michael Thompson (932-5010) for more information.
Sightings and Memberships: NatureSpeak is prepared by the Whistler Naturalists. To become a member or to report noteworthy sightings of mammals, birds, or other species, contact Lee Edwards (905-6448; e-mail: email@example.com).