A tiny, high pitched squee from a talus field precedes the sighting. Look carefully: the pika’s greyish-tan coat blends in well with sun-soaked boulders. If you’re lucky, you’ll catch a glimpse of the diminutive, chubby, round-eared rabbit relative that thrives in inhospitable environments.
Of all possible mountain encounters, crossing paths with a pika is my favorite. Marmots are cute but aggressive and liable to chew through tents, trekking-pole handles, and other necessities. Mountain goats killed a guy in my favorite national park. Bears are cool from a distance but stress-inducing up close (and bear hangs are a pain in the butt). Moose and mountain lions don’t have your best interests at heart, elk and deer are everywhere, and giant birds of prey are awesome but so far away. Pikas strike the right balance: adorable and totally non-threatening.
More importantly, the American pika is a crucial part of its local food chain. In Lake Tahoe, for instance, they’re important prey for owls, hawks, coyotes and weasels—which makes their disappearance from the area concerning.
According to a recently published study conducted in the North Lake Tahoe area, pikas have disappeared from their long-held homes in the scree fields of the Sierra Nevadas. Since 1910, the Lake Tahoe area has seen a 1.9°C rise in local temperature and a significant decline in snowpack, dramatically shrinking pika habitat. Biologist Joseph Stewart spent the last six years studying the impact of these changes in local climate on pika species. Specifically, he and a small team painstakingly scoured a 65-square-mile area over those six years and found plenty of past evidence of pika habitation, but not a single living pika. Pikas are typically easy for researchers to find; they’re loud and leave behind obvious traces. To identify sites of past inhabitation, researchers carbon-date pika excrement, among other techniques.
Pikas survive harsh winter weather thanks to a fiery metabolism and a thick coat of fur. They’re astoundingly adept at handling cold temperatures, but they lack a mechanism for cooling down beyond behavioral changes. During the summer, they’re busy gathering plants to bring back to their homes in boulder fields, stocking up for the winter ahead. Increasingly long, hot summer weather has proven unsurvivable for the hardy, hamster-sized creatures, whose only defense mechanism is to wait underground for the heat wave to pass. This restricts their ability to breed and gather food.
The extirpation of the species from their habitat near Tahoe is one of the most clear-cut examples we have of species being directly impacted by global warming. Stewart told KQED Science, “The loss of pikas from this large area of otherwise suitable habitat echoes prehistoric range collapses that happened when temperatures increased after the last ice age. This time, however, we’re seeing the effects of climate change unfold on a scale of decades as opposed to millennia.”
The Sierra Nevada isn’t the only place becoming inhospitable to pikas. In 2014 and 2015 in the Northwestern Great Basin, Nevada, researchers found twice as many relict sites—places that used to be hospitable to pikas and are no longer—than they did sites of active habitation. Pikas were spotted in 2011 in Zion National Park and in 2012 in Cedar Breaks National Monument in Utah, but can no longer be found in either area.
Despite the decline in American pika populations across the mountain west, the U.S. Fish and Wildlife Service has twice denied the pika endangered species status, once in 2010 and again in 2016.
Photos by Rob Oo (top), Jacob W. Frank/NPS.