Pika : how much higher?
Updated August 29, 2010
The small rabbit-like mammal whose high-pitched ‘eeek’ greets hikers on the trail to Jasper’s Cavell meadows – is fast becoming a bone of contention south of the border. It is all to do with climate change.
The pika (Ochotona princeps) has evolved to cope well with the cold temperatures of northern climates and higher elevations. It has a thick fur coat and – unlike its rabbit and hare cousins – has relatively small ears, short legs and virtually no tail: in other words no extremities susceptible to freezing. On the other hand these attributes put it at a distinct disadvantage when it comes to a warming climate; in fact researchers warn that it could die when exposed for more than a few hours to temperatures higher than 25.5 degrees Celsius.
For this reason the little animal has become the centre of a battle in the United States between environmentalists and the US Fish and Wildlife Service (FWS). In 2009, in response to a lawsuit launched by the Center for Biological Diversity (CBD) and Earthjustice, the FWS agreed to look into whether the pika should be listed as an endangered species because of its suspected inability to cope with global warming. This would have made it the first mammal in the lower 48 states to be listed because of climate change thereby compelling the government under the very strong US Endangered Species Act to actually start looking seriously at slowing global warming.
In February 2010 FWS decided against listing it as ‘endangered’, citing new research showing pikas can survive at more than 40 degrees Celsius and able to move higher if they need to avoid increased temperatures. CBD disagrees with this assessment stating that as most pikas already live in the higher elevations there is nowhere higher for many of them to go if they have to move out of the microclimate of their talus slopes. Already they have disappeared from more than a third of their previously known habitats in Nevada and Oregon; other populations have moved nearly 300m upslope from where they used to be found. Earthjustice has not ruled out a lawsuit against this decision.
This little bundle of grey-brown fur is well camouflaged in its rocky habitat. In fact the first indication of its presence will probably be its high-pitched squeak and even then it is difficult to locate because its squeak has a ventriloquial quality. It scurrys around the jumbled boulders that form safe hiding places and vantage points. Once stationary on a rock this smallest member of the rabbit family looks like just another little outcrop or bump.
Pikas live in northern areas of Europe and Asia and the mountains of central Asia. During the ice ages some crossed the Bering land-bridge to North America and settled in Alaska and mountainous areas further south. Some species of pika live in colonies but the one inhabiting the Rockies leads a solitary life outside the breeding season.
In Jasper National Park they can be found in many higher elevation areas with boulders and nearby grassy areas. They are fairly common in the Mount Edith Cavell area, particularly on the moraine flanking the side of the trail up to the meadows. They can also be seen near the trail crossing a large rock slide on the way up to the Whistlers Tramway upper terminal. There is even a small population at the north end of Medicine Lake. Because of their special habitat requirements pika colonies are relatively isolated from each other.
As you walk in pika habitat you may notice little piles of grasses and wildflowers lying in sunny patches on the rocks: these have been left by the little animal to dry out and provide a supply of ‘hay’ for the coming winter. The pika does not hibernate but spends the winter months sheltered under the boulders of a talus slope living off the summer’s harvest. These hay piles are critical to its survival and it will fiercely defend both them and its territory against others of its species.
Trips to its summer ‘hay field’ put it in danger of being taken by various predators – golden eagles, lynx, martens or wolverines. Even deep under the rocks it is not safe from the ermine or short-tailed weasel, which is slim and able to invade the pika runways.
Pika young – usually less than five – are born in May and sometimes there is a second brood later in the summer. However, as all the young have to be out and established in their own territories with hay piles by the time winter sets in the second brood rarely survives.
The rising summer temperatures of climate change force the pika to spend more time trying to keep cool under the rocks when it should be out collecting its supply of food for the coming winter. Added to that, a shallower winter snow pack leaves it with less insulation against the cold.
Life has never been easy for this little alpine species but now it may be getting a lot more difficult.