Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Southern Rocky Mountain pikas holding their own, says new CU-Boulder assessment

01.09.2011
Findings in contrast to recent study showing pika declines in the Great Basin

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.


American pikas are holding their own in the Southern Rocky Mountains, says new CU-Boulder study. Credit: Peter Erb

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 are higher in elevation and are more contiguous than habitats in Nevada's Great Basin, said Erb. But some climate models are predicting drier conditions in parts of the Southern Rockies in the coming decades as the climate warms, she said.

Alpine species are among the plants and animals most threatened by climatic shifts because of their physiological and geographic constraints, said Erb. In 2010, the U.S. government denied endangered species listing for the American pika in part because there was insufficient data on its distribution and abundance across western North America. The American pika lives in mountainous regions including British Columbia, Washington, Oregon, Idaho, Montana, Utah, Wyoming, Colorado, Nevada, California and New Mexico.

Surprisingly, most of the pikas that have disappeared from Great Basin sites under study in recent years were from sites that experienced extremely cold temperatures and may be related to a lack of winter snowpack insulation, said Ray, who has participated in several Great Basin pika studies including the 2011 study. Ray suspects pikas may reduce summer foraging activities to avoid heat stress caused by rising temperatures, leading to smaller winter food caches that can't sustain them during extreme cold snaps.

Guralnick, also curator of invertebrate zoology for the University of Colorado Museum of Natural History, said pikas are becoming a "bellwether" species for mountain ecosystems, primarily due to their recent Great Basin declines. Prior to the new CU survey, population trends of pikas in the Rockies were relatively unknown, he said.

"Many have assumed that warming temperatures would be the primary signal affecting North American pikas," said Guralnick. "This study shows it is more complicated than that, and that drier conditions could affect the persistence of pikas across the West."

The CU-Boulder study team initially looked at about 800 historical records of pika sightings in Colorado, New Mexico and Wyoming, but most locations were not specific enough for scientific use. The team eventually narrowed down the historical sites of pikas to 69 specific places known to have been occupied at some point before 1980, using tools like GPS to help pinpoint the geographical accuracy of each individual site.

Members of the rabbit family, the conspicuous pikas can be seen scurrying about rocky debris known as talus in alpine and subalpine regions of the Rockies, emitting their signature, high-pitched squeaks. Instead of hibernating, pikas cache huge amounts of plants and flowers known as hay piles under large rocks that sustain them through the long winters.

The CU team used data from Oregon State University's PRISM Climate Group to compile local climate information from 1908 to 2007 for the 69 historical pika sites in the Southern Rockies. The information produced estimates of monthly precipitation and minimum and maximum temperatures. The team confirmed the presence of pikas at each site either visually, by their distinctive squeaks, or by evidence of fresh pika hay piles cached under rocks in the study areas.

Sites visited early in the 2008 field season that lacked fresh pika signs were revisited in late October and early November for re-evaluation, Erb said. In places where pikas were still absent, researchers searched rock slopes up to two miles in all directions in an attempt to locate pika populations.

Volunteers have helped gather similar data on pikas through the PikaNET program, the Front Range Pika Project and the New Mexico Pika Monitoring Project. Such volunteer projects are organized through collaborations between CU-Boulder, the Colorado Division of Wildlife, the Denver Zoo, Rocky Mountain Wild, Colorado State University, the Mountain Studies Institute in Silverton, Colo., the San Juan Public Lands Center headquartered in Durango, Colo., and the Seventh Generation Institute in Santa Fe, N.M.

"It is good news that pikas are doing better in the Southern Rocky Mountains than some other places," said Erb. "It is likely that the geographic traits of the Rockies are a big reason why we are not seeing significant declines, at least not yet."

Editors: A video news story will be available at http://www.colorado.edu/news/ following the embargo lift on Sept. 1. A still image of an American pika is available at http://photography.colorado.edu/netpub/server.np?find&site=news&catalog=catalog&template=detail.np&field=itemid&op=matches&value=3572.

Contact:
Liesl Erb, 303-859-7803, Liesl.Erb@colorado.edu
Jim Scott, 303-492-3114, Jim.Scott@colorado.edu

Liesl Erb | EurekAlert!
Further information:
http://www.colorado.edu

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>