Snow depth does not affect recruitment in a low-density population of boreal woodland caribou (Rangifer tarandus caribou)
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- 作者：Nicholas C. Larter ; Thomas S. Jung…
- 关键词：Calf recruitment ; Caribou ; Northwest Territories ; Rangifer tarandus ; Snow depth
- 刊名：European Journal of Wildlife Research
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：63
- 期：1
- 全文大小：
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Zoology; Ecology; Fish & Wildlife Biology & Management;
- 出版者：Springer Berlin Heidelberg
- ISSN：1439-0574
- 卷排序：63
文摘
Winter snow depth may be an important driver of annual variability in recruitment of ungulate calves, and low calf recruitment has been implicated as a factor in declining boreal caribou (Rangifer tarandus caribou) populations. We used 11 consecutive years (2006–2016) of aerial survey data to document calf recruitment in a low-density population of boreal woodland caribou in the Northwest Territories, Canada. We measured snow depth in winter and tested two hypotheses: (1) that calf recruitment was lower in winters with greater snow depth and (2) that calf recruitment was lower following winters with greater snow depth (1-year time lag). Recruitment, the number of calves/adult female in March, ranged twofold from 0.23 to 0.45, and snow depth also ranged twofold from 41 to 85 cm. Yet, we found no support for the hypothesis that late-winter snow depth in the current or previous year was inversely related to calf recruitment.