Rocky talus slopes are vital habitat for thousands of species worldwide, including the American pika (Ochotona princeps), an iconic species of the North Cascades. In a warming climate, the talus interstitial spaces are critical to these sensitive mammals, buffering the effects of climate extremes. However, little is known about how the talus morphology affects subsurface temperature, in part because current techniques for measuring rock characteristics at the relevant scale are rudimentary. One aim of our research is to explore the long-term surface and subsurface temperature patterns in North Cascades National Park Service Complex (NOCA) and evaluate how talus characteristics influence them. The second aim of our research is to determine the rock characteristics pikas select for their haypiles. Pikas do not hibernate, spending most of the winter close to the haypiles they build during the summer. Haypiles are their main forage source during the winter when vegetation is scarce. To address these objectives, we developed a method using hand-held photogrammetry to map rocky habitats at a fine resolution (0.7mm-1.1mm) from which we can measure fine-scale characteristics of rock shape and size. This study will provide a method for continuous talus slopes characterization and a better understanding of pika habitat use, identifying what rock characteristics are most likely to maintain populations in the future.
Ana Ferreira
Washington State University
Presentation given at North Coast & Cascades Science Days, 2024
go.nps.gov/sciencedays
[NOCA]
28 сен 2024
