American Pikas show resiliency in the face of global warming

Date:
October 13, 2020
Source:
Arizona State University
Summary:
The American pika is a charismatic, diminutive relative of rabbits
that some researchers say is at high risk of extinction due to
climate change.

A new review finds that the American pika is far more resilient
in the face of warm temperatures than previously believed.



FULL STORY ==========================================================================
The American pika is a charismatic, diminutive relative of rabbits
that some researchers say is at high risk of extinction due to climate
change. Pikas typically live in cool habitats, often in mountains,
under rocks and boulders.

Because pikas are sensitive to high temperatures, some researchers
predict that, as the Earth's temperature rises, pikas will have to move
ever higher elevations until they eventually run out of habitat and
die out. Some scientists have claimed this cute little herbivore is the proverbial canary in the coal mine for climate change.


==========================================================================
A new extensive review by Arizona State University emeritus professor
Andrew Smith, published in the October issue of the Journal of Mammalogy,
finds that the American pika is far more resilient in the face of warm temperatures than previously believed. While emphasizing that climate
change is a serious threat to the survival of many species on Earth, Smith believes that the American pika currently is adapting remarkably well.

Smith has studied the American pika for more than 50 years and presents evidence from a thorough literature review showing that American pika populations are healthy across the full range of the species, which
extends from British Columbia and Alberta, Canada, to northern New Mexico
in the U.S.

Occupancy in potential pika habitat in the major western North American mountains was found to be uniformly high. Among sites that have
been surveyed recently, there was no discernible climate signal that discriminated between the many occupied and relatively few unoccupied
sites.

"This is a sign of a robust species," Smith said.

Smith said most of the studies that have raised alarms about the fate
of the pika are based on a relatively small number of restricted sites
at the margins of the pika's geographic range, primarily in the Great
Basin. However, a recent comprehensive study of pikas evaluating 3,250
sites in the Great Basin found pikas living in over 73% of the suitable
habitat investigated. Most important, the sites currently occupied by
pikas and the sites where they are no longer found were characterized
by similar climatic features.

"These results show that pikas are able to tolerate a broader set of
habitat conditions than previously understood," Smith adds.

Smith's most interesting finding is that pikas are apparently much more resilient than previously believed, allowing them to survive even at hot,
low- elevation sites. Bodie California State Historic Park, the Mono
Craters, Craters of the Moon National Monument and Preserve, Lava Beds
National Monument, and the Columbia River Gorge (all hot, low-elevation
sites) retain active pika populations, demonstrating the adaptive capacity
and resilience of pikas. Pikas cope with warm temperatures by retreating
into their cool, underground talus habitat during the hot daylight hours
and augment their restricted daytime foraging with nocturnal activity.

This doesn't mean that some pika populations have not been pushed to their limit, leading to their disappearance from some habitats. Smith's review
points out that most documented cases of local loss of pika populations
have occurred on small, isolated habitat patches.

"Due to the relatively poor ability of pikas to disperse between areas,
those habitats are not likely to be recolonized, particularly in light
of our warming climate," Smith said. "In spite of the general health
of pikas across their range, these losses represent a one-way street,
leading to a gradual loss of some pika populations. Fortunately for
pikas, their preferred talus habitat in the major mountain cordilleras is larger and more contiguous, so the overall risk to this species is low." Smith's work emphasizes the importance of incorporating all aspects of a species' behavior and ecology when considering its conservation status,
and that all available data must be considered before suggesting a species
is going extinct. For the American pika, the data conclusively show that
rather than facing extinction, American pikas are changing their behaviors
in ways that help them better withstand climate change, at least for now.


========================================================================== Story Source: Materials provided by Arizona_State_University. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Andrew T Smith. Conservation status of American pikas (Ochotona
princeps). Journal of Mammalogy, 2020; DOI: 10.1093/jmammal/gyaa110 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201013164411.htm

--- up 7 weeks, 1 day, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)