Center for Ecosystem Sentinels, Department of Biology, University of Washington, Seattle, Washington, USA.
Botswana Predator Conservation, Wild Entrust, Maun, Botswana.
J Anim Ecol. 2024 Nov;93(11):1785-1798. doi: 10.1111/1365-2656.14192. Epub 2024 Oct 4.
Droughts are increasing in frequency and severity globally due to climate change, leading to changes in resource availability that may have cascading effects on animal ecology. Resource availability is a key driver of animal space use, which in turn influences interspecific interactions like intraguild competition. Understanding how climate-induced changes in resource availability influence animal space use, and how species-specific responses scale up to affect intraguild dynamics, is necessary for predicting broader community-level responses to climatic changes. Although several studies have demonstrated the ecological impacts of drought, the behavioural responses of individuals that scale up to these broader-scale effects are not well known, particularly among animals in top trophic levels like large carnivores. Furthermore, we currently lack understanding of how the impacts of climate variability on individual carnivore behaviour are linked to intraguild dynamics, in part because multi-species datasets collected at timescales relevant to climatic changes are rare. Using 11 years of GPS data from four sympatric large carnivore species in southern Africa-lions (Panthera leo), leopards (Panthera pardus), African wild dogs (Lycaon pictus) and cheetahs (Acinonyx jubatus)-spanning 4 severe drought events, we test whether drought conditions impact (1) large carnivore space use, (2) broad-scale intraguild spatial overlap and (3) fine-scale intraguild interactions. Drought conditions expanded space use across species, with carnivores increasing their monthly home range sizes by 35% (wild dogs) to 66% (leopards). Drought conditions increased the amount of spatial overlap between lions and subordinate felids (cheetahs and leopards) by up to 119%, but only lion-cheetah encounter rates were affected by these changes, declining in response to drought. Our findings reveal that drought has a clear signature on the space use of multiple sympatric large carnivore species, which can alter spatiotemporal partitioning between competing species. Our study thereby illuminates the links between environmental change, animal behaviour and intraguild dynamics. While fine-scale avoidance strategies may facilitate intraguild coexistence during periodic droughts, large carnivore conservation may require considerable expansion of protected areas or revised human-carnivore coexistence strategies to accommodate the likely long-term increased space demands of large carnivores under projected increases in drought intensity.
由于气候变化，干旱在全球范围内的频率和严重程度都在增加，导致资源可用性发生变化，这可能对动物生态学产生级联效应。资源可用性是动物空间利用的关键驱动因素，而空间利用反过来又会影响种间相互作用，如种内竞争。了解气候引起的资源可用性变化如何影响动物的空间利用，以及物种特有的反应如何扩大到影响种内动态，对于预测更广泛的社区层面的气候变化反应是必要的。尽管有几项研究已经证明了干旱对生态的影响，但个体的行为反应，以及这些更广泛的效应，还不是很清楚，特别是在像大型食肉动物这样的顶级捕食者动物中。此外，我们目前还不了解气候变化对个体食肉动物行为的影响如何与种内动态相关联，部分原因是在与气候变化相关的时间尺度上收集的多物种数据集很少。本研究利用南部非洲四种共生大型食肉动物（狮子、豹、非洲野犬和猎豹）的 11 年 GPS 数据，共跨越 4 次严重干旱事件，检验了干旱条件是否会影响（1）大型食肉动物的空间利用，（2）种内广泛的空间重叠，以及（3）种内精细的相互作用。干旱条件扩大了物种的空间利用范围，食肉动物的月活动范围大小增加了 35%（野犬）到 66%（豹）。干旱条件增加了狮子和从属猫科动物（猎豹和豹）之间的空间重叠量，最多增加了 119%，但只有狮子和猎豹的遭遇率受到这些变化的影响，这些遭遇率随着干旱而下降。我们的研究结果表明，干旱对多种共生大型食肉动物的空间利用有明显的影响，这可能会改变竞争物种之间的时空分割。我们的研究因此揭示了环境变化、动物行为和种内动态之间的联系。虽然在周期性干旱期间，精细的回避策略可能有助于种内共存，但大型食肉动物的保护可能需要相当大的保护区扩张，或修订人类与食肉动物共存的策略，以适应预计在干旱强度增加的情况下，大型食肉动物的空间需求可能长期增加。
