Interannual variability: a crucial component of space use at the territory level.
Interannual variability: a crucial component of space use at the territory level.
复制标题
年际变化：领土层面空间利用的重要组成部分。
DOI：
10.1890/13-2116.1
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发表时间：
2015
期刊：
影响因子：
4.8
通讯作者：
Douglas W. Smith
中科院分区：
文献类型：
--
作者：
A. Uboni;J. Vucetich;D. Stahler;Douglas W. Smith
空间利用的年际变化以及这种变化如何受到依赖于密度和不依赖于密度的因素的影响是种群生态学中的重要过程。然而，年际变化被大多数空间利用研究所忽视。我们评估了13年来(1996-2008年)黄石国家公园内15个不同狼群的狼的变化。我们估计了利用率分布，以量化每年夏季和冬季每个种群领地内的空间使用强度。然后，我们使用交叉口体积指数(VI)来量化空间使用的年际变化程度。这一指数既考虑了重叠的面积，也考虑了整个领土使用强度的差异，范围在0到1之间。VI指数的平均值为0.49，差异很大，大约20%的观测值(n=230)是<；0.3或>；0.7。在夏季，42%的差异可归因于不同群体之间的差异。这些差异可以归因于后天习得的行为，从未被认为对空间使用有如此大的影响。在冬季，34%的年际重叠变化可归因于降水量和种群大小的年际差异。这一结果揭示了气候对捕食者空间利用的强烈影响，并强调了了解气候因素在气候变化发生时如何影响捕食者种群的重要性。我们没有发现重叠与代表密度依赖的过程(麋鹿和狼的密度)或种内竞争(狼与麋鹿的比率)的变量之间有任何显著的关联。最后一个结果对捕食者-食饵系统的经典观点提出了挑战。在小的空间尺度上，捕食者的空间利用可能是由猎物分布以外的因素驱动的。
Interannual variability in space use and how that variation is influenced by density-dependent and density-independent factors are important processes in population ecology. Nevertheless, interannual variability has been neglected by the majority of space use studies. We assessed that variation for wolves living in 15 different packs within Yellowstone National Park during a 13-year period (1996-2008). We estimated utilization distributions to quantify the intensity of space use within each pack's territory each year in summer and winter. Then, we used the volume of intersection index (VI) to quantify the extent to which space use varied from year to year. This index accounts for both the area of overlap and differences in the intensity of use throughout a territory and ranges between 0 and 1. The mean VI index was 0.49, and varied considerably, with approximately 20% of observations (n = 230) being <0.3 or >0.7. In summer, 42% of the variation was attributable to differences between packs. These differences can be attributable to learned behaviors and had never been thought to have such an influence on space use. In winter, 34% of the variation in overlap between years was attributable to interannual differences in precipitation and pack size. This result reveals the strong influence of climate on predator space use and underlies the importance of understanding how climatic factors are going to affect predator populations in the occurrence of climate change. We did not find any significant association between overlap and variables representing density-dependent processes (elk and wolf densities) or intraspecific competition (ratio of wolves to elk). This last result poses a challenge to the classic view of predator-prey systems. On a small spatial scale, predator space use may be driven by factors other than prey distribution.