The American Pika: Subsistence farming at treeline
For most of us in Whistler, winter is a time to be anticipated with visions of deep powder, warm fireplaces, and hot toddies. But for some winter is a drag – a time of icy roads, cold feet, and frozen lakes – a time to escape! The geese and human snowbirds pack up and head south. Bears and marmots binge and sleep through it all. But for those who lack the mobility to travel or the lethargy to sleep for five months the only solution is to hunker down and tough it out.
For some creatures genetic programming provides a seemingly spontaneous accommodation to winter that requires no forethought or preparation. Weasels, ptarmigan, and rabbits find themselves turning white, a recurrent gift of camouflage to help them survive the winter. Others, like mice and voles simply grow a thick coat of fur and carry on life beneath the snow. But some creatures must actively prepare to survive. The legendary hoarding of winter food by squirrels is probably no less driven by genetic programming than the colour change of rabbits, but it gives the appearance of planning – a precognition of hard times ahead.
The Pika or "rock rabbit" must rank as nature's ultimate planner. Unrelated to true rabbits, pikas belongs to the family Ochotonidae , of which only two species are found in North America. Our local Pika ( O. princeps ) makes its home among frost-heaved boulders and talus slopes near subalpine meadows. Weighing less than half a pound and only 8 inches from harelipped mouth to tailless bum this diminutive, chinchilla-like animal is protected from severe winter cold by a fine, dense fur.
Though fairly abundant on both Whistler and Blackcomb, Pikas are more often heard than seen. Their enigmatic, high-pitched "eep" has earned them the name "ventriloquist of the mountains." It takes patience to locate the source of the sound. Sitting motionless, near the entrance to a cleft in the rock, they become almost invisible against the lichen-covered boulders. But though the animal itself is hard to see its hay-making activity is obvious. For Pikas putting in a stock of winter food is a two-stage process. The green plants are cut and carried to a sunny ledge to dry before being stacked in the maze of rocky tunnels where the hay-maker will live and remain active throughout the next winter.
Obsessed with preparing for hard times, Pikas begin restocking their larders before the spring snow has even melted. Around Harmony Lake it is common to see bundles of freshly cut Western Anemone set out to dry on a rock ledge while new blooms are only beginning to emerge from the receding snow.
Pikas occupy and vigorously defend the same territory for their entire five-to-six year lifetime. Females, left to struggle as "single moms," commonly raise two small litters each year. And though life is tough, what with weasels and all, the resourceful Pika has learned to survive winter through hard work and planning ahead.
More on Mushrooms: Thanks to Todd Bush for leading last week’s mushroom walk. And thanks to the almost 60(!) participants for their great attitude during our oversubscribed event. We’ll make sure the next mushroom walk is a little more intimate. Watch here for details.
Last week’s column dealt with the impressive size of the Short-stemmed Russula. This week’s model, Eddie ("Hip") Jim, enjoys how his Russula hat keeps him dry while also making a great fashion statement (Photo: Bob Brett.).
Written by: Jack Souther