JACKSON, Wyo. — Experts consider Grand Teton National Park (GTNP) to be great pika habitat, where the species is widely distributed and shows little evidence of decline.
Erik Beever, who’s been researching American pikas across the western U.S. since 1994 in 14 different regions, is currently part of a five-year study on pikas in GTNP. The study, which started in 2022, follows other pika projects in the Park completed from 2014 to 2016 and 2019 to 2021. From what’s been seen so far, Beever calls GTNP pikas’ “happy place.”
“Pika distribution was predicted…to remain at nearly 100 percent in Grand Teton, to the end of the 21st Century.”
Erik A. Beever
“Pika distribution was predicted in a study using field sampling during 2010 and 2011 to remain at nearly 100 percent in Grand Teton, to the end of the 21st Century,” Beever says. “And our research since 2014 really seems to affirm that.”
Conversely, that same study predicted pika populations in Yellowstone National Park were set to decline, a prediction supported by data from Beever’s recently published research. He says more investigation and more samples are needed.
The only evidence that points to possible Grand Teton pika decline is at the very lowest elevation of their distribution in the Park, which Beever says are the warmer, driest spots. The talus patches in these spots have widely distributed and copious amounts of old fecal pellets, which is what suggests that pikas may have been more numerous in past years.
Because American pikas are a cold-adapted species, it makes sense that sites where pikas are gone are warmer across all of summer, more frequently very hot in summer and receive more precipitation compared to sites where pikas remain. However, what may seem surprising is that it’s also more frequently very cold in the places where pikas have disappeared.
Based on a study Beever was part of in the Great Basin (spanning Nevada, Oregon and California), he says very cold temperatures in low-snow years have become a problem for pikas across parts of their range, where insulating snowpack is absent from the spaces between the rocks.
Although there’s not any data yet collected on how pikas are being impacted by the low snow this year in the Tetons, Beever notes that repeatedly, across different research domains, evidence has shown that very low snow winters and low spring rain or snow typically lead to strong declines in pika populations.
Beever says water balance overall, particularly ecological water availability, is proving to be a big part of the equation where pika persistence is concerned, given results from numerous studies. He says that’s one of the questions researchers are asking in GTNP.
“We’re just starting to realize that,” Beever says. “We’re increasingly finding that water balance is part of what differentiates where pikas are [currently] from where they used to be.”
Going forward, Beever emphasizes that despite the positive local numbers, a discussion about rain and snow is going to continue to be part of the investigation being done.
