LONG-CALL PLAYBACK: A NOVEL METHOD FOR ESTIMATING DENSITY AND OCCUPANCY OF NORTH AMERICAN PIKA | |||
| Chris J Smith; University of Nevada at Reno, Tahoe Campus; chrissmith@unr.edu; Matt Shinderman, Lyle Nichols, Joseph Stewart, Mila Opalenik, Kevin Shoemaker | |||
Developing efficient techniques for monitoring populations of climate-sensitive species is crucial for understanding impacts of climate change. American Pika (Ochotona princeps) are a small heat-sensitive lagomorph, that in some regions are experiencing local extirpations, apparently due to warming climates. Surveys for pikas often rely on direct detections (aural or visual) and, in some studies, rely on interpretation of whether sign (i.e., haypiles, scat) appears fresh enough to indicate current occupancy. Both pika and passerine birds exhibit vocal defense of small exclusive territories, and we trialed longcall playback using point-count methods on pika, a technique commonly employed in bird surveys. We estimated density and occupancy rates of pikas in a range of environments, comparing these estimates and detection probability to standard occupancy surveys. Overall, playback increased direct detection rates by 2.3-3 times, with detection probability ranging between 80-97% in ideal conditions (within 4 hours of sunrise/sunset and < 7°C on the first visit). The benefits of playback were especially apparent in structurally complex lava, where standard occupancy surveys missed ~90% of pikas. We suggest that playback with point count or territory mapping- style surveys, common in bird research, are more efficient (5-15 min per 2500m2) than standard occupancy surveys (20-30 min per 450m2) and can be easily added as a tool for pika research across the west. | |||
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