The American pika, a small flower-gathering relative of the rabbit, may be one of the first mammals in North America known to fall victim to global warming if heat-trapping emissions are not reduced soon.
American pikas are typically found in rocky areas, called talus, within alpine regions of the western United States and southwestern Canada. Many hikers, while passing through pika habitat in these rocky areas, have heard these shy creatures call and whistle to each other.

Since food is difficult to obtain in winter in the alpine environment, pikas cut, sun-dry, and later store vegetation for winter use in characteristic 'hay piles.' They are often called 'ecosystem engineers' because of their extensive haying activities.

According to research, global warming appears to have contributed to local extinctions of pika populations. American pikas may be the 'canary in the coal mine' when it comes to the response of alpine and mountain systems to global warming. Find out how you can become part of the solution to global warming and help American pikas.

Physical Features

American pikas are smaller relatives of hares and rabbits, but have short, round ears. They are grayish-to-brown mammals frequently seen hunched up on boulders of nearly the same color. They have no visible tail and typically measure 6 1/5 to 8 1/2 inches and weigh between 4 and 6 1/3 ounces.

Diet

American pikas feed primarily on grasses and herbs. Since food is difficult to obtain in winter in the alpine environment, pikas cut, sun-dry, and later store vegetation for winter use in characteristic 'hay piles' on a rock in talus areas, and pikas are sometimes observed gathering wildflowers.

Habitat and Distribution

American pikas live where few people ever go--they are usually found in rocky areas, called talus, within alpine regions of the western United States and southwestern Canada. They may be spotted among some of the talus slopes along trails and roads in Glacier National Park; also in Crater Lake, Kings Canyon, Mount Rainier, Rocky Mount, Sequoia, Yellowstone, and Yosemite National Parks.

Behavior

Pikas have a vocal repertoire that consists of a series of peculiar short squeaks. They are active only by day and do not hibernate in winter. Pikas are colonial, and each pika has its territory within the colony.

American pikas are often called 'ecosystem engineers' because of their extensive haying activities. They breed in spring and possibly in summer, and their young are born between May/June and July/August, usually with between two and five in a litter. The gestation period is about 30 days.

Threats

Research suggests that American pikas are particularly vulnerable to global warming because they reside in areas with cool, relatively moist climates like those normally found in their mountaintop habitat. As temperatures rise due to increasing emissions of CO2 and other heat-trapping gases, many montane animals are expected to seek higher elevations or migrate northward in an attempt to find suitable habitat. Living essentially on high-elevation islands means that American pikas in these regions have little option for refuge from the pressures of climate change because migration across low-elevation valleys represents for them an incalculably high risk - and perhaps an impossibility under current climate regimes. Results from a new study suggest that climate may be interacting with other factors such as proximity to roads and smaller habitat area to increase extinction risk for pikas, creating detrimental synergistic effects.

American Pika Research

According to recent research by USGS ecologist Dr. Erik Beever, global warming appears to have contributed to local extinctions of pika populations in the Great Basin area - the area between the Sierra Nevada and Rocky Mountains - during the last part of the 20th century.
American pikas disappeared from seven of twenty-five studied areas. WWF is funding the re-sampling of these pika populations to find out how they vary across shorter time scales. If the global warming trend is not reversed soon through a significant reduction in emissions of CO2 and other heat-trapping gases, population losses of the American pika may lead to the animal's disappearance.

Previous research results suggested that American pikas are particularly vulnerable to global warming because they reside in areas with cool, relatively moist climates like those normally found in mountaintop habitats. As temperatures rise due to increasing emissions of heat-trapping gases, many alpine animals are expected to seek higher elevations or migrate northward in an attempt to find suitable habitat. Yet, American pikas in these regions have little option for escape from the pressures of climate change because migration across low-elevation valleys represents an incalculably high risk-and perhaps an impossibility under current climate regimes-for them. Results from the study suggest that climate may be interacting with other factors such as proximity to roads and smaller habitat area to increase extinction risk for pikas, creating harmful synergistic effects.

The pikas' particular vulnerability to global warming is due to several factors. American pikas cannot easily migrate in response to climate change, as their habitat is currently restricted to small, disconnected habitat "islands" in numerous mountain ranges. Although talus within mountain ranges is often more continuous, this is not always the case; some ranges only have habitable talus at lower elevations or in broadly separated patches. Furthermore, American pikas generally do not appear to move large distances, as many individuals may spend their entire lifespan within a half-mile radius. Pikas do not inhabit burrows which could mitigate extreme temperatures and are highly active aboveground during the hottest months of the year. In the warmer months, pikas must cure vegetation for their overwinter survival as pikas are active year-round and food is scarce in winter in the alpine environment. Earlier maturation of vegetation associated with global warming may mean increased stress for pikas, and hotter temperatures during high activity periods can create direct thermal stress on the animals. Pikas are densely furred, and thus cannot dissipate heat easily.