American Pika population on the decline due to climate change

“American Pika” by NPS Climate Change Response is marked with CC PDM 1.0. To view the terms, visit

American Pika’s are a small, generalist herbivores that live on high elevation mountains west of the Rocky Mountains, ranging from Montana down to Utah. Today there are fewer than 1,000 that exist worldwide and with such a low population they are still not under the Endangered Species Act (  The typical habitat climate for an American Pika are cool and moist conditions that rarely go over freezing temperatures and if exposed to temperatures in the 70’s it can be detrimental and fatal (

American Pika’s are sentinel species, meaning they are used to detect risks to humans by giving an advance warning of danger that is to come.  Most of the time humans use sentinel organisms to judge when a pollutant has become an issue because they are able accumulate a pollutant in their body without adverse effects. However, the reason we are watching American Pika is to detect ecological effects of climate change (Wilkening et al., 2013).

There is a major anthropogenic cause destroying the entire population of the American Pika and that is climate change. Climate change is due to the release of carbon dioxide and other greenhouse gasses that become trapped in the atmosphere and degrades our planets ozone layer. Climate change leads to an increase in global temperature, change in weather patterns, and more severe storms. With how sensitive American Pika’s are to temperature changes the slightest increase in temperature can lead to damaging physiological effects within their bodies. To combat this increase in temperatures over the past decade we have seen their range rise by 150 meters (492 feet) in the Great Basin over the past decade (Wilkening et al., 2013).

A shift in the environment that they inhabit can produce multiple stressors that can have cascading effects within their bodies.  When exposed to stressors the body releases glucocorticoids through a three-step process. Glucocorticoids sound scary, but really it is just a hormone that is associated with stress and can have a major impact on the body. The goal of glucocorticoid is to help the animal deal with the stressor they are encountering and bring their body back to equilibrium. By doing this the body shuts down and reduces multiple systems within in order to have access to the maximum amount of energy it can.

From glucocorticoids testing through fecal matter researchers have seen that American Pika’s have been releasing GCs in short burst, which increases their change of survival as well as helps them bring their bodies back to an equilibrium state (Wilkening et al., 2013). When an animal is exposed to a stressor for an extended period it can lead to chronic stress within the animal creating a long-term excretion of glucocorticoid. With a long-term excretion of glucocorticoid their bodies won’t be able to reach equilibrium and as glucocorticoids are being release their immune system will be weakened making them more susceptible to diseases.



O’Mara, C. (2021). American pika. National Wildlife Federation. Retrieved March 22, 2022, from

Sullivan, P. (2022). Natural History (American Pika). Natural history. Retrieved March 22, 2022, from

Wilkening, J. L., Ray, C., & Sweazea, K. L. (2013). Stress hormone concentration in Rocky Mountain populations of the American pika (Ochotona princeps). Conservation Physiology, 1(1).