Winter has come to the ski slopes above Los Alamos. A walk through the area shows all of the slopes now covered by snow – the silence is profound except when the ski lifts are running.
As people ride the lifts to the top of the mountain, they pass over a mass of broken rock without realizing that small creatures, icons of the high country, are just a few feet below them.
Pikas are the icons who rest quietly in their rocky dens, waiting for spring. A talus slope of snow-covered broken rock forms a roof above them and hides them from any passing skiers.
Unlike other mammals, they are not hibernating but living on the plants they have stored away. During the summer, pika industriously harvested plants, placed them at the entrances of their burrows to dry in then sun, and then stored them underground for winter food.
The pikas can be seen in the summer by anyone willing to sit quietly by the scree slope, waiting for them to appear. Pikas are not quiet, but make high-pitched squeaks to one another while foraging for plants. Like the rabbits to which they are related, pikas are cute to watch.
Pikas are adapted in several ways to their environment. They are high-altitude specialists, typically living at 9,000 feet or higher. They live specifically in the openings among the jumble of rocks that make talus slopes on the sides of mountains.
Their physiology allows them to live in the cool temperatures that are typical of high elevations. Indeed, a pica is likely to die if exposed even briefly to air temperatures greater than 79 degrees.
Pajarito Mountain pika. Photo by Chick Keller
A pika munching a leaf along the Cerro Grande Trail. Photo by Sally King
It is this last characteristic that makes pikas a possible indicator for climate change. One analysis of population data collected for throughout North America suggests that pikas will disappear from mountains that are lower in elevation or in the southern part of the continent. This pattern would be consistent with increasing climate temperature.
The following continental map shows both the predicted distribution of the American pika and where they may become extinct. (Blue means unlikely, red means likely to become extinct.)
The approximate present distribution of the species is outlined in yellow. (Data from Nature Serve, organized by Dr. Scott Loarie for a National Geographic report.)
A careful look at the map shows that pikas that live in the high mountains of Colorado are projected to survive global climate change because of being higher and more northerly than New Mexico.
The pikas in the Jemez Mountains, in contrast, are projected to die out in coming decades. Will the pika on the Los Alamos ski slopes become extinct?
Pika survival in western state habitats: likely (red) or unlikely (blue.) Map by Dr. Scott Loarie for National Geographic News Watch
A more detailed map of the Jemez Mountains shows elevations above 9,000 feet in green. There are only three large areas in which the mountains tops are at least 9,000 in elevation. The Los Alamos ski slopes are in one these three areas. The pikas are living on islands in a surrounding sea of rising air temperature.
Areas in New Mexico above 9,000 feet shown in green. Map enhancement by Robert Dryja
But is the situation this simple? Other research reports that pikas in California apparently are doing well. The air temperature inside of pika nests has been measured and found to be much cooler inside than outside.
Pika may go to their underground nests when air temperature rises and makes them uncomfortable. The research also reports that the California pikas have extensive good habitat with moisture — not small areas like in the Jemez Mountains.
The Great Basin area of Nevada is particularly dry, with higher average local temperatures. Climate change, habitat, and local temperature all are working against pikas in this area.
In effect, the negative impact of climate warming at a local level may be offset or reinforced. Pica in California may be in good habitats, but those in Nevada are not.
So what may be happening to the Los Alamos ski slope pikas? On the negative side, there is the impact of climate change. Additionally, local air temperatures may be higher due to the slope facing to east and so receiving more direct sun light.
On the positive side, the area receives moisture in the form of snow, rain, and cloud cover. The pika may go to their nests under the rocks when it becomes too warm for them.
There may be an accidental side benefit for the pikas due to the creation of the ski slopes’ being created by the cutting of conifers. Grasses and forbs now grow in the place of some trees and so provide additional plant forage for the pikas.
A talus slope with a pika colony is adjacent to one ski slope. Perhaps the creation of this ski slope made it possible for pikas to inhabit this area.
A monitoring program of the ski slope pikas could be established to better determine what may be happening. If you are interested in developing or helping with a monitoring program, then send a message to firstname.lastname@example.org at the Pajarito Environmental Education Center.