American pika: the adorable trolls of the mountain tops — The Environmental Issue

American Pika (Ochotona princeps)

The Environmental Issue: Climate Change.

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American pika http://now.howstuffworks.com

As lovable as pika are, their charm has been no match for the relentless effects of climate change. High in the mountain talus, organisms specialized to the high alpine environment, such as pika, are especially vulnerable to the effects of climate change due their precise adaptations to the montane ecosystem. Specifically, pika have a variety of behavioral and physical adaptations to survive in the extreme weather conditions of the mountains. Behaviorally, pika use the talus for shelter from extreme thunder and winter storms, as well as for thermoregulation in both the winter and summer. With a layer of snow resting on top, the talus functions as insulation and, in the heat of the direct summer sun, as a cold oasis. Physically, pika have adapted to wear an extremely thick coat to insulate their small bodies in the harsh winters and they are highly specialized in terms of thermal biology with only a narrow temperature window for survival. This narrow temperature window, or rather the lethal temperature limit, is arguably the largest threat to species survival because in the case of their body temperature reaching outside of these limits, the pika will die. Even if the ambient temperature outside a pika’s talus field reaches 80°F, they can die in 30 minutes in poorly-insulated talus.

pika1
http://ecowest.org

Unfortunately, there has been an increase in the number of summer days that have reached that temperature in the last 20 years. Average monthly and yearly temperatures have been increasing at alarming rates across all of the mountain tops in which America pika reside. Usually in cases of increased home range temperatures, animals, like elk, will migrate up in elevation, but the pika are already on the tops of the mountains and so there is nowhere higher and cooler for them to go. Likewise, recent lower winter precipitation rates in the mountains have left summers drier and hotter and winters colder than ever before due to the lack of snowpack and thus spring snowpack melt. Survival rates of pika are often predicted by both climate- and vegetation-based factors because the food they need is also being negatively impacted by the changing climate. Biologists have found that the populations that are at highest risk for declining density and extirpation are likely to be those in habitat sites with extreme human presence, poor-quality vegetation, or higher summer maximum temperatures. Multiple studies done in the Great Basin observed 25 historic pika populations have found that 11 have already vanished. Whats even more troubling, is that the extirpation rates have increased from one extirpation every 10.7 years to one every 2.2 years! Those populations that vanished were noted to have the greatest average temperature increase as well as greatest average precipitation decrease.

American pika (Ochotona princeps) running

Given all of the dramatic changes threatening pika and their habitat, they are still not listed under the Endangered Species Act after numerous attempts. The U.S. Fish and Wildlife Service has repeatedly denied the species listing due to “a lack of evidence” supporting that pika could not adapt under a warmer and drier climate.

Biologists are continually studying pika populations to learn more about how we can help protect pika and their beautiful montane homes. Some studies have noted that perhaps there is a beacon of hope as some individual pika in specific populations have shown signs of foraging at night – an activity that needs further study, but could mean that some of the pika are trying to adapt to the changes.

Looking forward, we can only hope that pika are adapting, but adaptation doesn’t happen overnight and often, even in quick scenarios, it can take centuries. But, until then let us hope that maybe someday, someday soon, pika will find a home on the Endangered Species List and have the federal habitat protection they need to survive.

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If you would like to check out more animals on the Endangered Species List on your own, please visit the U.S. Fish and Wildlife Service’s list of Threaten/Endangered Species in the U.S. and Foreign Countries.

References: 
Beever, E. A.; Brussard, P. F.; Berger, J. Patterns of Apparent Extirpation Among Isolated Populations of Pikas (Ochotona princeps) in the Great Basin. J. Mammal. 2003, 84 (1), 37–54. (accessed Feb 27, 2017).

Beever, E. A.; Dobrowski, S. Z.; Long, J.; Mynsberge, A. R.; Piekielek, N. B. Understanding relationships among abundance, extirpation, and climate at ecoregional scales. Ecology 2013, 94 (7), 1563–1571. (accessed Feb 27, 2017).

Erb, L. P.; Ray, C.; Guralnick, R. Determinants of pika population density vs. occupancy in the Southern Rocky Mountains. Ecol. Appl. 2014, 24 (3), 429–435. (accessed Feb 27, 2017).

Galbreath, K. E.; Hafner, D. J.; Zamudio, K. R. When cold is better: Climate-driven elevation shifts yield complex patterns of diversification and demography in an alpine specialist (american pika, Ochotona princeps).  Evolution (N. Y). 2009, 63 (11), 2848–2863. (accessed Feb 27, 2017).

Howell, A. H. North American Fauna No. 47 Revision of the American pikas (Genus Ochotona). U.S. Dep. Agric. Bur. Biol. Surv. 1924, 47. (accessed Feb 27, 2017).

Kreuzer, M. P.; Huntly, N. J. Habitat-specific demography: evidence for source-sink population structure in a mammal, the pika. Oecologia 2003, 134 (3), 343–349. (accessed Feb 27, 2017).

Millar, C. I.; Westfall, R. D. Distribution and Climatic Relationships of the American Pika (Ochotona princeps) in the Sierra Nevada and Western Great Basin, U.S.A.; Periglacial Landforms as Refugia in Warming Climates. Arctic, Antarct. Alp. Res. 2010, 42 (4), 493–496. (accessed Feb 27, 2017).

Moilanen, A.; Hanski, I.; Smith, A. T. Long‐Term Dynamics in a Metapopulation of the American Pika. Am. Nat. 1998, 152 (4), 530–542. (accessed Feb27, 2017).

Moritz, C.; Patton, J. L.; Conroy, C. J.; Parra, J. L.; White, G. C.; Beissinger, S.R., C. Impact of a Century of Climate Change on Small-Mammal Communities in Yosemite National Park, USA. Science. 2008, 322 (5899), 261–264. (accessed Mar 1, 2017).

Morrison, S. F.; Hik, D. S. Demographic analysis of a declining pika Ochotona collaris population: Linking survival to broad-scale climate patterns via spring snowmelt patterns. J. Anim. Ecol. 2007, 76 (5), 899–907. (accessed Mar 1, 2017).

Moyer-Horner, L.; Beever, E. A.; Johnson, D. H.; Biel, M.; Belt, Predictors of Current and Longer-Term Patterns of Abundance of American Pikas (Ochotona princeps) across a Leading-Edge Protected Area. J. PLoS One 2016, 11 (11). (accessed Mar 1, 2017).

Wilkening, J. L.; Ray, C.; Beever, E. A.; Brussard, P. F. Modeling contemporary range retraction in Great Basin pikas (Ochotona princeps) using data on microclimate and microhabitat. Quat. Int. 2011, 235 (1–2), 77–88. (accessed Feb 27, 2017).

Yandow, L. H.; Chalfoun, A. D.; Doak, D. F. Climate tolerances and habitat requirements jointly shape the elevational distribution of the American pika (Ochotona princeps), with implications for climate change effects. PLoS One 2015, 10 (8), 1–21. (accessed Mar 1, 2017).

Images:
Image 1: LePrieur, T. Furry Friday: Pikas. http://www.birdscalgary.com/wp-content/uploads/2016/10/image1-1.jp (accessed Feb 27, 2017).

Image 2: S-Eyekaufer. Things Are Looking Up For the Adorable American pika. http://cdn.now.howstuffworks.com/media-content/E4Wufjrq-pika_seyerkaufer_gettyimagesjpg-1210-680.jpg (accessed Feb 27, 2017). 

Image 3: Tobin, M. American pika in Indian Peaks Wilderness, CO. http://ecowest.org/2013/09/24/video-mountain-species-climate-change-and-the-escalator-effect/ (accessed Mar 1, 2017).

Image 4: Leeson, T,P. Where Species Will Find Refuge. http://www.hcn.org/issues/48.22/can-microclimates-offer-safe-havens-for-threatened-species/web-pika-snow-jpg/image (accessed Mar 1, 2017). 

Image 5: Unknown. Citizen Science and the Joy of Pika. http://www.science-live.org/pikas/follow/wp-content/uploads/2016/10/L4C0163-2k.jpg (accessed Mar 1, 2017).

 

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