Evaluating dall's sheep habitat use via camera traps
Abstract
Anthropogenic disturbances, such as military training, potentially affect mountain ungulate populations. Assessing the spatiotemporal occupancy or habitat use of a wildlife population can assist with planning of potentially disrupting activities. Currently, military training is expanding into potential Dall's sheep (Ovis dalli dalli) habitat within 2 training areas of Fort Wainwright, Alaska. The 2 study areas included Molybdenum Ridge, a 10‐km long geologically isolated granite ridgeline on the northern periphery of the Alaska Range and Black Rapids Training Area, a steeper and smaller area within the mountain range and bordered by the Delta River. The United States Army requires a better understanding of sheep habitat use in these 2 areas to identify how training could affect the population and to reduce overlap of training and high sheep occupancy. We used an array of 54 spatially balanced camera traps, taking triggered and hourly time lapse images, to determine Dall's sheep habitat use based on seasonal and site covariates. Camera traps operated for a continuous 15‐month sampling period and captured nearly 8,000 images of sheep. Our occupancy models indicated that abiotic covariates such as slope, snow depth, and distance to escape terrain were the most important factors determining habitat use. Seasonal differences in habitat use indicated higher use during winter and spring for Molybdenum Ridge, and higher habitat use during the summer for Black Rapids Training Area. Detection probabilities were constant temporally and were higher if the camera was positioned on a wildlife trail versus off trail. Our results suggest that the best opportunity to minimize training interactions with Dall's sheep is to conduct training in early‐July to early‐September, specifically in areas with 500 m from escape terrain. © 2017 The Wildlife Society.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 04, 2017
- Source ID
- 10.1002/jwmg.21308
Entities
People
- Aleya R. Brinkman
- Calvin F. Bagley
- Elizabeth S. Neipert
- Jeremy S. Dertien
- John A. Haddix
- Paul F. Doherty Jr.
Organizations
- Colorado State University
- United States Army Corps of Engineers