Vail Daily column: Alpine rabbits?
July 21, 2013
While many of the little ones in our valley are on summer break, there is no respite in the warm months for the diminutive American pika. Pika are members of the lagomorph family, which also includes rabbits and hares. They lack the long rabbit ears that make their cousins easily distinguishable, but make their presence known with high-pitched calls that echo through the alpine talus fields.
Pika are territorial critters and their call is one way they ward off neighbors and rivals. They guard their home ranges (which span up to about 400 square yards) ferociously because food is scarce above 8,500 feet. Because of the short growing season and scattered patches of grasses and forbs that they rely on for food, pika keep very busy during the summer months gathering hay to help carry them through the winter. Unlike other alpine species such as marmots, pika do not hibernate through the cold winter months. Instead, they remain active under the snow, slowly devouring their stockpiles of hay, which may total one to two bushels at the start of the winter (almost enough to fill a bathtub). The collection of such a granary is no small task for a creature measuring 7 inches and weighing in at about 8 ounces.
Pikas spend the summer gathering green plants and drying them in the sun on rocks. They then stash their hay piles in smaller quantities among the rocks within their territory. The span of their hay pile complex may reach more than 100 square yards, ensuring that food will always be close by when the grasses have died and snow begins to fall.
While few predators prowl the pika's alpine habitat, mustelids such as weasels and martens are well-equipped to stalk and capture them. Pika rely on talus and scree fields with gaps between the rocks large enough for them to hide and travel for protection. They develop a system of nooks and pathways within their territory, which allows them to disappear from sight in an instant, seeming to re-appear a few rocks or boulders away. Long, slender hunters such as weasels are among the few carnivores that can navigate the same narrow passages that pika travel.
Pikas spend the summer gathering green plants and drying them in the sun on rocks. They then stash their hay piles in smaller quantities among the rocks within their territory.
In the harsh alpine ecosystem however, predators are likely a small concern for the pikas as they gather grasses and prepare for the long, cold winter season. If you are hardy enough to climb up to the elevations where pika scurry in the summer months, chances are good you will hear one. The hard surfaces of the rocks and shrill pitch of the pika's call make it seem as if they can throw their voices, so seeing one can be another challenge altogether.
Pete Wadden is the field research educator at Walking Mountains Science Center. He too enjoys scrambling over the rocks in high alpine talus fields in the summer, but seldom does so as adeptly as the little pika.