A warm-weather pika gathers more moss
The American pika (Ochotona princeps) maybe one of the world’s cutest faces for global warming. It is a round, furry mammal that lives in the mountains of the American west. If you are out hiking in the summer in Utah, Colorado or Oregon, you can sometimes hear them call to each other in high-pitched little voices.
Some mountain areas have become too warm for pikas. They are disappearing from some of them as warm temperatures drive them away. But one population of pikas has figured out how to thrive in a warmer world: by gathering a lot of moss. And now, you can help scientists find out more about how pikas live, eat and behave by going on a pika watch.
Pikas are well suited for colder mountain life. Their round shape and thick fur help their bodies conserve heat. But that also means they don’t do well in warmer climates. Pikas can’t sweat or release heat well when they need to stay cool. While 78 degrees Fahrenheit (25.5 degrees Celsius) is a nice summer day to you and me, a pika will die after only two hours in that kind of heat.
To stay cool, pikas live high in the mountains on rockslides. In the summer, pikas forage out above the rocks, gathering plants and collecting them into “haypiles” that they store under the rocks. In the winter, these haypiles serve as winter pantries, and the rockslides provide nooks and crannies where the pikas can stay warm. The rockslides also provide shelter from the summer’s heat. But when you’re stuck under a rock, you can’t collect food. So warmer summers means pikas don’t store as much food for the winter. Some populations of pikas have been disappearing as the weather gets too hot for them to handle.
But there’s one population of pikas that has figured out how to survive when things get hot. The Columbia River Gorge is near sea level, which means it gets a lot warmer than it does on top of a mountain. It should be way too hot for pikas. But there’s a population of pikas living there anyway. How do they do it? Johanna Varner and M. Denise Dearing from the University of Utah in Salt Lake City, Utah set out to find out how the pikas of the Columbia River Gorge make their living.
In a study published December 17 in the Journal of Mammology, Varner and Dearing report that pikas in the Columbia River Gorge eat a diet that is 60 percent moss. This is impressive because moss isn’t a very desirable food. Moss is so high in fiber that Varner says that it’s “like eating paper.” It isn’t very nutritious. The pikas might have to eat a lot of moss to get the nutrition they need, but it appears to be worth it. The moss grows on the rockslides where they live, so they don’t have to venture out in danger of overheating or getting eaten by predators. Moss also grows on the rockslides all year round, so pikas don’t have to work so hard to maintain their haypiles to stay fed through the winter. “They are basically living in the grocery store,” Varner says, “and it’s open all winter.”
But because moss isn’t very nutritious, pikas produce a special kind of poop called caecal pellets. The pikas then eat these soft pellets. By running the same pile of moss through their stomachs twice, they can get more nutrition out of their food. It may not be pretty, but a pika has to do what a pika has to do.
The Columbia River Gorge pikas show that the animals can adapt to the climate as it gets warmer by changing what they eat and where they get their food.
Now, Varner and her colleagues need citizen scientists to help find out more about pikas. The scientists want to set up temperature monitors to look at where the pikas go to keep cool. And they need your help to watch for pikas. You can sign up at the website for the Cascades Pika Watch. The scientists can train you in how to watch for pikas. When you go out on a hike, you can sit and observe them and record what you see and hear. When you get back home, you can submit your data online. Your pika observations could help scientists learn more about how pikas stay cool when life gets hot.
caecal pellets A type of feces produced by rodents like rabbits and pikas. These are poop pellets that are only partially digested. The pika can then eat the caecal pellet, and pass the food through again, letting its stomach get a second chance at digestion.
climate The weather conditions prevailing in an area in general or over a long period.
climate change Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.
Columbia River Gorge The narrow valley that runs through southern Washington and northern Oregon. It runs through the Cascades mountain range and the Columbia River flows through it.
haypile A pile of stored plants. Pikas store plants for the winter in haypiles underneath the rocks.
nutrition The supply of materials that all organisms need to stay alive. These materials include things like sugars, fats and proteins. The type of nutrition that each animal needs depends on what kind of animal it is and what it has evolved to eat. Herbivores can get all the nutrition they need from plants. Carnivores can get their nutrition from meat. Omnivores can eat both plants and animals to get the nutrition they need.
pika Any member of the family Ochotonidae. These are lagomorphs, and closely related to rabbits and hares. They live in cold climates all over the world, including Asia, North America, and Europe. They live in rocky areas, and collect plants during the summer into haypiles which last them through the winter. Pikas are known for their high pitched alarm calls.