Pikas are active year-round and live mainly in talus slopes and boulder fields. Their sharp "enk" call is a characteristic sound along the many talus and boulder fields in Denali. Pikas are highly territorial. While many pikas may inhabit a talus slope, individuals actively guard their territories and food caches.
Pikas do not hibernate and they do not store much body fat. To maintain their year-round active lifestyle, pikas establish several food caches in their territories. Pikas forage throughout the short subarctic summer and store many different types of vegetation in their caches. Pikas will also forage on lichens and other low-lying vegetation under the snow during winter. Once thought to be strict vegetarians, researchers working in western Canada found that pikas living on isolated nunataks (isolated islands of rocks in the middle of glaciers) filled their caches with the small songbirds that did not survive migration. Using stable isotope analyses, these researchers found that not only do these pikas cache songbirds, but they eat them as well. Whether or not pikas in Denali display similar dietary habits is unknown, but it is certainly possible, particularly for pikas living in glacially-dominated areas.
Pikas live on an ecological edge of survival. Their survival depends on their ability to store food, gather food once their caches are depleted, and endure the long subarctic winter. They are particularly vulnerable to changing weather conditions. During winter, many pikas may die if there is not enough snow to provide them with insulation from the cold. A late spring, with delayed production of plant material, may mean that pikas don’t have enough time to prepare caches for winter. Changes in Denali’s weather patterns resulting from global climate change present pikas with another challenge to their survival.
Did You Know?
The vast landscapes of interior Alaska are changing. Large glaciers are receding, permafrost is melting and woody plants are spreading. Comparison of "then-and-now" photographs and data from major vegetation monitoring should allow detection, understanding and potential management of these changes.