Aliperti Jaclyn R, Jenderseck Kimberly, Van Vuren Dirk H
Department of Wildlife, Fish, and Conservation Biology University of California Davis CA USA.
Rocky Mountain Biological Laboratory Crested Butte CO USA.
Ecol Evol. 2022 Aug 29;12(8):e9241. doi: 10.1002/ece3.9241. eCollection 2022 Aug.
Investigating individual-based habitat settlement decisions is a central theme in ecology, yet studies that quantify density-dependent habitat selection or tie fitness to resource selection decisions remain rare. We quantified habitat selection in golden-mantled ground squirrels () across two spatial scales (home-range placement, and occurrence within the home range) by using 11 consecutive years of data on individual space use, and we used resource selection functions and multilevel modeling to address how habitat preferences may be influenced by density or linked to fitness outcomes. Squirrels preferred dry meadow over other habitat types (wet meadow, aspen, spruce, and willow) at both spatial scales. Squirrels were more likely to use dry meadow that contained shorter vegetation and vision-enhancing prominences such as rocks ("perches"). The use of dry meadow at each scale was not influenced by changes in density. The use of dry meadow did not lead to increased litter size, pre-hibernation mass, or survival. However, squirrels that experienced a greater number of perches or lower local densities had higher survival rates. Our results suggest that a lack of visual obstruction, probably facilitating detection of predators, drives habitat selection in this system. Surprisingly, squirrels maintained their preference for dry meadow as density increased, and they experienced reduced survival as a result. This work furthers our understanding about the causes and consequences of changes in habitat use, informing wildlife management and conservation.
研究基于个体的栖息地定居决策是生态学的核心主题，但量化密度依赖性栖息地选择或将适合度与资源选择决策联系起来的研究仍然很少。我们利用连续11年关于个体空间利用的数据，在两个空间尺度（家域位置以及家域内的出现情况）上量化了金背地松鼠的栖息地选择，并使用资源选择函数和多水平模型来探讨栖息地偏好如何受到密度的影响或与适合度结果相关联。在两个空间尺度上，松鼠都更喜欢干燥草地而非其他栖息地类型（湿地草甸、白杨、云杉和柳树）。松鼠更倾向于利用植被较短且有岩石（“栖木”）等能增强视野的突出物的干燥草地。在每个尺度上，干燥草地的利用不受密度变化的影响。利用干燥草地并未导致产仔数增加、冬眠前体重增加或存活率提高。然而，经历较多栖木或较低局部密度的松鼠存活率更高。我们的结果表明，缺乏视觉阻碍（可能有助于发现捕食者）驱动了该系统中的栖息地选择。令人惊讶的是，随着密度增加，松鼠仍保持对干燥草地的偏好，结果它们的存活率降低了。这项工作进一步加深了我们对栖息地利用变化的原因和后果的理解，为野生动物管理和保护提供了信息。
