Conflicts in National Parks: A case study of helicopters and bighorn sheep time budgets at the Grand Canyon
Stockwell CA, Bateman GC, Berger J. 1991. Conflicts in National Parks: A case study of helicopters and bighorn sheep time budgets at the Grand Canyon. Biological Conservation. 56:317-328
Wildlife in numerous national parks of the United States experience frequent overflights by aircraft. Such activities may disturb wildlife populations. We analysed time budgets for desert bighorn sheep Ovis candensis nelsoni in the presence and absence of helicopter overflights at Grand Canyon National Park (GCNP) to determine the extent to which food intake may be impaired. Bighorn were sensitive to disturbance during winter (43% reduction in foraging efficiency) but not during spring (no significant effect). This seasonal difference may have arisen because the sheep were farther from helicopters during the spring after they had migrated to lower elevations. Further analysis indicated a disturbance threshold of 250-450m. The conservation implications of these results are discussed.
- Type
- Journal Article
- Authors
- Stockwell, Craig; Bateman, Gary; Berger, Joel
- Units
- ARD , GRCA
- Keywords
- Absence (Biodiversity), acoustic sensitivity, Aircraft, Artiodactyla (Even-Toed Ungulates), Bioacoustics, Bovidae (Bovids), disturbance sensitivity, Foraging, human-induced impacts, Mammalia (Mammals), Ovis canadensis nelsoni (Nelson's Bighorn Sheep), Presence (Biodiversity), SOUNDBIB, Taxa Links To References