Expert Says American Pikas Are More Climate-Resilient Than Many Think
The potato-sized rabbit-cousin called the pika has long stood as a coalmine canary for global warming.
But a research review in the Journal of Mammalogy suggests the role of human-induced climate change in its decline might be overblown.
"This has sort of become a mantra or a drum beat for a lot of the press releases that have come out on pikas," said Arizona State University pika expert Andrew Smith, who wrote the paper.
Smith isn't a climate denier. He just thinks American pikas (Ochotona princeps) aren't the right poster animals for human induced climate change.
"I thought that it was time to set the record straight and write sort of a comprehensive review and underline why people think they're going extinct, and why they're not going extinct."
American pikas dwell in cool, wet mountain uplands. So when they began to disappear from their more fringe territories, global warming seemed a likely culprit. After all, pika range boarders are known to have retreated where warmer conditions prevailed after the last ice age.
But Smith, who also performs assessments for the International Union for Conservation of Nature Red List of Threatened Species, found the rock-dwelling foragers still mostly thrive across their range. Though populations of the tailless, round-eared mammals are decreasing, the Red List still classifies them as a species of least concern.
But they're still worth keeping an eye on, says Smith.
"They also actually do possess a lot of the characteristics of species that we think might be threatened with extinction."
American pikas dwell on rocky heaps at the feet of steep cliffs. Solitary and territorial, they can eat only the vegetation around their rock piles. And their females have small litters, rearing around two young per year.
"And they really are a climate-sensitive animal," said Smith.
But they also show surprising resilience, occupying spots seemingly too hot or dry for comfort. American pikas adapt to such conditions by sleeping in rocky hollows by day and foraging at dawn or dusk.
Smith believes the small mammals' disappearance from fringe zones actually stems from behavioral and physical limitations that keep them from recolonizing distant areas following after die-offs.
Moreover, he said local extinctions don't always arise from climate factors, and added that researchers should document other causes such as predation, grazing and trapping. As an example, he cited sites listed in a paper from the 1990s: One was a borrow pit for road construction; another was as a garbage dump; and a third was littered with shotgun shells.
"As a scientist, if I had been confronted with that, I would have said, 'Well, these sites are off the charts, and so we will not count them,' because it could easily be that the extinctions were caused by things other than climate change."