Variation in subsurface thermal characteristics of microrefuges used by range core and peripheral populations of the American Pika (Ochotona princeps)
Rodhouse TJ, Hovland M, Jeffress MR. 2017. Variation in subsurface thermal characteristics of microrefuges used by range core and peripheral populations of the American Pika (Ochotona princeps). Ecology and Evolution. 7:1514-1526
Microrefuges provide microclimates decoupled from inhospitable regional climate regimes that enable range peripheral populations to persist and are important to cold-adapted species in an era of accelerated climate change. However, identifying and describing the thermal characteristics of microrefuge habitats is challenging, particularly for mobile organisms in cryptic, patchy habitats. We examined variation in subsurface thermal conditions of microrefuge habitats among different rock substrate types used by the American pika (Ochotona princeps), a climate-sensitive, rock-dwelling Lagomorph. We compared subsurface temperatures in talus and lava substrates in pika survey sites in two US national park units; one park study area on the range periphery and the other in the range core. We deployed paired sensors to examine within-site temperature variation. We hypothesized that subsurface temperatures within occupied sites and structurally-complex substrates would be cooler in summer and warmer in winter than unoccupied and less complex sites. Although within-site variability was high, with correlations between paired sensors as low as 47%, we found compelling evidence that pikas occupy microrefuge habitats where subsurface conditions provide more thermal stability than in unoccupied microhabitats. The percentage of days in which microhabitat temperatures were between -2.5° C and 25.5° C was significantly higher in occupied sites. Interestingly, thermal conditions were substantially more stable (P<0.05) in the lava substrate type identified to be preferentially used by pikas (pahoehoe vs. a’a) in a previous study. Our study and others suggest that thermal stability appears to be the defining characteristic of subsurface microrefuges used by American pikas and is a likely explanation for enigmatic population persistence at the range periphery. Our study exemplifies an integrated approach for studying complex microhabitat conditions, paired with site use surveys and contextualized with information about gene flow provided by complementary studies.
- Type
- Journal Article
- Authors
- Rodhouse, Thomas; Hovland, Matthew; Jeffress, Mackenzie
- Units
- CRLA , CRMO , UCBN
- Keywords
- American pika, biogeography, climate, distribution, Mammals, monitoring, persistence, range periphery, UCBN Journal Article
See also
- Analysis of proposed rock quarrying and trail improvement impacts on American pikas in Grand Teton National Park
- Craters of the Moon National Monument and Preserve Bats
- Distribution of a climate-sensitive species at an interior range margin
- Distribution of American Pikas in a Low-elevation Lava Landscape: Conservation Implications from the Range Periphery
- Habitat availability and gene flow influence diverging local population trajectories under scenarios of climate change: a place-based approach
- Landscape effects on gene flow for a climate-sensitive montane species, the American pika
- Modeling Connectivity and Gene Flow of American Pikas in the Western United States
- Monitoring the American pika (Ochotona princeps) in the Pacific West Region - Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: Protocol Narrative Version 1.0
- Monitoring the American pika (Ochotona princeps) in the Pacific West Region - Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: Standard Operating Procedures Version 1.0 (Appendix to Narrative Version 1.0)
- Monitoring the American pika (Ochotona princeps) in the Pacific West Region - Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: Standard Operating Procedures Version 1.1 (Appendix to Narrative Version 1.0)
- Pika Monitoring at Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: 2010 Annual Monitoring Report
- Pika monitoring at Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: 2010-2014 report
- Pika monitoring under way in four western parks: The development of a collaborative multipark protocol
- Pikas in Peril Research Project: Crater Lake National Park - Summary and results
- Pikas in Peril Research Project: Craters of the Moon National Monument and Preserve - Summary and results
- Replicated landscape genetic and network analyses reveal wide variation in functional connectivity for American pikas
- Replicated landscape genetic and network analyses reveal wide variation in functional connectivity for American pikas
- The idiosyncrasies of place: geographic variation in the climate-distribution relationships of the American pika
- The idiosyncrasies of place: geographic variation in the climate-distribution relationships of the American pika