You know the Pokemon character Pikachu? Cute, right? The inspiration for that squeaky little guy is the American pika, which lives in the high altitude, windswept, mountainous regions of the Western United States and Canada. They resemble rodents, but these tough little mammals are actually lagomorphs, a group of strictly herbivorous animals that includes just rabbits, hares and pika.
Pikas Are Like Vocal Rabbits
American pikas spend their days mowing the grass in montane meadows, providing meals for owls and weasels and, like all lagomorphs, eating their own feces. They even make two kinds of poop — one dry pellet they leave behind, and one softer, more nutrient-rich one they save as a snack for later. Some populations of pikas tend to cache, or store, plants high in phenolic toxins — the same chemicals that make red wine and coffee taste astringent. These chemicals aren't great for the pika's digestive systems in large quantities, but when the toxins decay over time in hay piles (the piles of plant matter pikas collect and store for their winter food supply), they act as an antimicrobial agents, helping to preserve the plant biomass over winter.
Unlike most rabbits and hares, pikas often use a variety of loud vocalizations to communicate with each other. They're individually territorial but form loose "colonies" of a handful of animals that sound vocal alarms to help warn each other when predators or threats like other trespassing pikas come around.
"These calls are regionally variable as dialects," says Johanna Varner, assistant professor of biology at Colorado Mesa University. "A pika in Colorado may have a different pitched call than one in Utah or California or Oregon."
Pikas Are Seriously Heat Intolerant
American pikas don't hibernate during the cold mountain winters — in fact, they can survive all manner of inclement weather, but they simply can't tolerate heat: They start dying off if the temperature rises above around 75 degrees Fahrenheit (24 degrees Celsius).
This is due to their extremely high metabolic rate, which helps them generate heat during the long, cold mountain winters. A high metabolic rate leads to a high resting body temperature — close to 104 degrees Fahrenheit (40 degrees Celsius), which for humans is an unspeakably high fever. It's also very high even for a pika, but they keep their internal temperature pretty close to what's lethal. Compared with American pikas, humans have almost twice the number of degrees between our resting body temperature and a killing fever.
"Pikas have very low thermal conductance through their rabbit-like fur, so they retain body heat better than many other mammals of their size," says Chris Ray, a researcher at the Institute for Arctic and Alpine Research at the University of Colorado Boulder. "They have no adaptations for shedding heat actively through panting, sweating or exposing bare skin. These physical traits help them survive winters, but summertime activities can push a pika's temperature into the lethal zone if it doesn't have access to cool places where it can shed heat passively."
A pika's heat intolerance means that global climate change is even more pressing an issue for them than many other terrestrial animals. Because they live in little islands on the tops of mountains, there is really no way for them to migrate to cooler places, and with recent record-breaking high temperatures here on Earth, American pikas have been retreating farther up mountain peaks.
The National Park Service Climate Change Response Program designed a protocol specifically to address pika recovery, although the pika was denied official federal endangered species protections in 2010. Had it been listed, it would have been the first animal listed as endangered due to climate change. Although it's currently considered a Species of Least Concern, scientists have been able to quantify its shrinking numbers. However, the pika climate change task force was shut down in 2016.
"My personal opinion is that it's difficult to justify concern over pikas when there are still millions of them persisting in the wild, and because there is little we can do to save them other than change the trend in global temperature," says Ray. "However, we can perhaps mitigate some effects of temperature by reducing other threats like introduced pathogens and predators or trends in nutrient availability."
According to Varner, the declines in pika numbers seem to be regionally variable — there are declining numbers in some populations and in certain parts of their range, but some others seem more stable — or at least are not declining as precipitously.
Which is a good thing. And now, just for fun, here's a little pika doing his very best Freddie Mercury: