As the American pika decreases in population, scientists are worried the downward trend is related to climate change.

According to the Santa Cruz Sentinel, authors of a study published in the Journal of Biogeography believe higher temperatures are causing the mountain-dwelling pikas living in lower altitudes to decrease in number.

"This same pattern of extinctions at sites with high summer temperatures has also been observed in the Great Basin region," study lead author Joseph Stewart, a graduate student at the University of California, Santa Cruz (UCSC), said in a press release. "Backpackers and hikers often see pikas scurrying back and forth across the rocks, gathering little bouquets of wildflowers in their mouths.

"They are uniquely adapted to cold temperatures, but these same adaptations make the species vulnerable to global warming."

Stewart called the findings "troubling" and further proves climate change as an issue with wide ranging consequences.

"Hikers often see them hopping across the rocks and carrying little bouquets of wildflowers in their mouth," Stewart told the Sentinel. "A lot of the locations that hikers go to, the lower elevations for pikas, that's where we're losing them.

"A bird just has to pick up and fly.

"If a pika wants to get from one mountain peak that isn't cold enough to another one that is colder, oftentimes it's going to have to go down into hotter, lower-elevation areas. The problem is their habitat doesn't go high enough in California."