Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA.
Department of Zoology and Entomology, University of Fort Hare, Alice, South Africa.
Ecology. 2021 May;102(5):e03319. doi: 10.1002/ecy.3319.
Competitively dominant carnivore species can limit the population sizes and alter the behavior of inferior competitors. Established mechanisms that enable carnivore coexistence include spatial and temporal avoidance of dominant predator species by subordinates, and dietary niche separation. However, spatial heterogeneity across landscapes could provide inferior competitors with refuges in the form of areas with lower competitor density and/or locations that provide concealment from competitors. Here, we combine temporally overlapping telemetry data from dominant lions (Panthera leo) and subordinate African wild dogs (Lycaon pictus) with high-resolution remote sensing in an integrated step selection analysis to investigate how fine-scaled landscape heterogeneity might facilitate carnivore coexistence in South Africa's Hluhluwe-iMfolozi Park, where both predators occur at exceptionally high densities. We ask whether the primary lion-avoidance strategy of wild dogs is spatial avoidance of lions or areas frequented by lions, or if wild dogs selectively use landscape features to avoid detection by lions. Within this framework, we also test whether wild dogs rely on proactive or reactive responses to lion risk. In contrast to previous studies finding strong spatial avoidance of lions by wild dogs, we found that the primary wild dog lion-avoidance strategy was to select landscape features that aid in avoidance of lion detection. This habitat selection was routinely used by wild dogs, and especially when in areas and during times of high lion-encounter risk, suggesting a proactive response to lion risk. Our findings suggest that spatial landscape heterogeneity could represent an alternative mechanism for carnivore coexistence, especially as ever-shrinking carnivore ranges force inferior competitors into increased contact with dominant species.
竞争优势明显的肉食动物可以限制较弱竞争者的种群数量和改变其行为。使肉食动物能够共存的既定机制包括下属动物通过时空回避优势捕食者物种，以及食性生态位分离。然而，景观的空间异质性可以为较弱的竞争者提供避难所，形式包括竞争密度较低的区域和/或可以躲避竞争者的位置。在这里，我们将来自优势狮子（ Panthera leo ）和从属非洲野狗（ Lycaon pictus ）的时间重叠遥测数据与高分辨率遥感相结合，通过综合的步长选择分析来研究在南非的 Hluhluwe-iMfolozi 公园中，精细的景观异质性如何促进肉食动物共存，因为这两个捕食者都以异常高的密度存在。我们询问野狗的主要狮子回避策略是回避狮子还是狮子经常出没的区域，还是野狗会选择性地使用景观特征来避免被狮子发现。在这个框架内，我们还测试野狗是否依赖于主动或被动反应来应对狮子的风险。与之前的研究发现野狗强烈回避狮子的情况相反，我们发现野狗的主要狮子回避策略是选择有助于避免狮子探测的景观特征。野狗经常使用这种栖息地选择，尤其是在狮子相遇风险较高的区域和时间，这表明它们对狮子的风险有主动反应。我们的研究结果表明，空间景观异质性可能是肉食动物共存的另一种机制，尤其是在肉食动物的范围不断缩小迫使较弱的竞争者与优势物种增加接触的情况下。
