Mount Rainier National Park and Olympic National Park elk monitoring program annual report 2015
Happe P, Vales DJ, Moeller BJ, Tirhi M, Holman E, Beirne K, Baccus WT, Chestnut T. 2016. Mount Rainier National Park and Olympic National Park elk monitoring program annual report 2015. Natural Resource Data Series. NPS/NCCN/NRDS—2016/1041. National Park Service. Fort Collins, Colorado
Fiscal year 2015 was the eighth and sixth year of gathering data in Mount Rainier (MORA) and Olympic (OLYM) respectively according to the approved elk monitoring protocol (Griffin et al. 2012 for the North Coast and Cascades Network (NCCN)). Elk monitoring in these large wilderness parks relies on aerial surveys from a helicopter. The number of missed elk during aerial surveys is estimated by applying site-specific models that account for detection bias (Griffin et al. 2012). Summer surveys are intended to provide quantitative estimates of abundance, sex and age composition, and distribution of migratory elk in high elevation trend count areas. 2015 was the hottest year in record in Seattle, and the earliest recorded date of snowmelt at Paradise in MORA over the 8 years that these surveys have been conducted. These climate conditions had an influence on plant phenology (Figure 1) and consequently may have influenced elk use of high elevation meadows and subsequently the elk survey results. At MORA the South trend count unit was surveyed twice and the North unit was surveyed once. We counted only 280 and 189 elk during the replicate surveys of the South Rainier trend count area, and 297 elk in the North Rainier trend count area. Using the model to correct for detection bias, we estimated that 427 and 319 elk were in the South trend count area, and 408 elk were in the North trend count area at the time of the respective surveys. Estimates of abundance that ranged from 37-69% greater than the raw counts represented the correction for negative detectability biases associated with many of the observed elk groups occurring in small groups under relatively difficult detection conditions (i.e., high concealment of vegetation). One trend count areas at OLYM - the Core - was surveyed completely. We counted only 72 in the Core. Using the model to correct for detection bias, we estimated that 107 elk were in the Core at the time of the surveys (i.e., a 49% upward adjustment due to detection biases). Additional flights scheduled for OLYM were canceled due to the abnormally low numbers of elk seen in the survey frame in the Core.
- Type
- Published Report
- Authors
- Happe, Patti; Vales, David; Moeller, Barbara; Tirhi, Michelle; Holman, Eric; Beirne, Katherine; Baccus, William; Chestnut, Tara
- Date of Issue
- 2016-08
- Publisher
- National Park Service
- Units
- MORA , OLYM
- Keywords
- Abundance, Aerial Survey, annual report, Cervus elaphus nelsoni, Cervus elaphus roosevelti, Composition, detection bias, Distribution, double-observer sightability model, Elk Monitoring, Elwha, Helicopter, High Elevation, Hoh, migratory, Monitoring, Mount Rainier National Park, NCCN, North Coast and Cascades Network, North Rainier, North Rainier herd, Olympic National Park, population trend, Queets, Quinault, Rocky Mountain Elk, Roosevelt Elk, sightability model, South Rainier, South Rainier herd, summer range, trend count, Winter Range
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Mammals