American pikas, the chirpy, potato-sized denizens of rocky debris in mountain ranges and high plateaus in western North America, are holding their own in the Southern Rocky Mountains, says a new University of Colorado Boulder study.
Led by CU-Boulder doctoral student Liesl Erb, the study team assessed 69 historical sites known to host pikas in a swath of the Southern Rockies ranging from southern Wyoming through Colorado and into northern New Mexico. The results showed that 65 of the 69 historical sites that had hosted pikas -- some dating back more than a century -- were still occupied by the round-eared, hamster-like mammals, Erb said.
The new study stands in contrast to a 2011 study in Nevada's Great Basin that showed local extinction rates of pika populations there have increased nearly five-fold in the past decade. That study, by a separate research group, also showed that local Great Basin pika populations had moved up in elevation nearly 500 feet in the past 10 years, a migration believed to be triggered by warming temperatures.
Despite the low number of extirpations, or local population extinctions, in the Southern Rockies, the CU-Boulder team found that the pattern of pika disappearance at particular sites was not random, said Erb of the ecology and evolutionary biology department and lead study author. "The sites that had been abandoned by pikas in our study area all were drier on average than the occupied sites," she said.
A paper on the new CU-Boulder study by Erb is being published in the September issue of the journal Ecology. Co-authors include CU-Boulder Research Associate Chris Ray and Associate Professor Robert Guralnick, both affiliated with the ecology and evolutionary biology department.
The study was funded primarily by the National Geographic Society.
One likely reason for the relative success of pikas in the Southern Rocky Mountains study is that available habitats a
|Contact: Liesl Erb|
University of Colorado at Boulder