文章基本信息

标题：Adapting sampling plans to caribou distribution on calving grounds
其他标题：Adapting sampling plans to caribou distribution on calving grounds
本地全文：下载
作者：Michel Crête ; Louis-Paul Rivest ; Didier Le Hénaff 等
期刊名称：Rangifer
印刷版ISSN：1890-6729
出版年度：1991
卷号：11
期号：4
页码：137-150
DOI：10.7557/2.11.4.1004
语种：English
出版社：Swedish University of Agricultural Sciences
摘要：Between 1984 and 1988, the size of the two caribou herds in northern Québec was derived by combining estimates of female numbers on calving grounds in June and composition counts during rut in autumn. Sampling with aerial photos was conducted on calving grounds to determine the number of animals per km2, telemetry served to estimate the proportion of females in the census area at the time of photography in addition to summer survival rate, and helicopter or ground observations were used for composition counts. Observers were able to detect on black and white negatives over 95 percent of caribou counted from a helicopter flying at low altitude over the same area; photo scale varied between = 1:3 600 and 1:6 000. Sampling units covering less than 15-20 ha were the best for sampling caribou distribution on calving grounds, where density generally averaged » 10 individuals-km"2. Around 90 percent of caribou on calving grounds were females; others were mostly yearling males. During the 1-2 day photographic census, 64 to 77 percent of the females were present on the calving areas. Summer survival exceeded 95 percent in three summers. In autumn, females composed between 45 and 54 percent of each herd. The Rivière George herd was estimated at 682 000 individuals (± 36%; alpha = 0.10) in 1988. This estimate was imprecise due to insufficiens sample size for measuring animal density on the calving ground and for determining proportion of females on the calving ground at the time of the photo census. To improve precision and reduce cost, it is proposed to estimate herd size of tundra caribou in one step, using only aerial photos in early June without telemetry.
关键词：Population Ecology; Caribou Census;caribou; census; aerial photography; George River herd; Rivière George; Riviere aux Feuilles