Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA.
Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA.
Ecol Appl. 2019 Mar;29(2):e01845. doi: 10.1002/eap.1845. Epub 2019 Jan 29.
Carnivore communities face unprecedented threats from humans. Yet, management regimes have variable effects on carnivores, where species may persist or decline in response to direct or indirect changes to the ecosystem. Using a hierarchical multispecies modeling approach, we examined the effects of alternative management regimes (i.e., active vs. passive enforcement of regulations) on carnivore abundances and group sizes at both species and community levels in the Masai Mara National Reserve, Kenya. Alternative management regimes have created a dichotomy in ecosystem conditions within the Reserve, where active enforcement of regulations maintains low levels of human disturbance in the Mara Triangle and passive enforcement of regulations in the Talek region permits multiple forms of human disturbance. Our results demonstrate that these alternative management regimes have variable effects on 11 observed carnivore species. As predicted, some species, such as African lions and bat-eared foxes, have higher population densities in the Mara Triangle, where regulations are actively enforced. Yet, other species, including black-backed jackals and spotted hyenas, have higher population densities in the Talek region where enforcement is passive. Multiple underlying mechanisms, including behavioral plasticity and competitive release, are likely causing higher black-backed jackals and spotted hyena densities in the disturbed Talek region. Our multispecies modeling framework reveals that carnivores do not react to management regimes uniformly, shaping carnivore communities by differentially producing winning and losing species. Some carnivore species require active enforcement of regulations for effective conservation, while others more readily adapt (and in some instances thrive in response) to lax management enforcement and resulting anthropogenic disturbance. Yet, high levels of human disturbance appear to be negatively affecting the majority of carnivores, with potential consequences that may permeate throughout the rest of the ecosystem. Community approaches to monitoring carnivores should be adopted as single species monitoring may overlook important intra-community variability.
食肉类动物群落正面临着人类带来的前所未有的威胁。然而，管理体制对食肉类动物的影响各不相同，因为物种可能会因生态系统的直接或间接变化而持续存在或减少。我们使用分层多物种建模方法，在肯尼亚马赛马拉国家保护区，检查了替代管理体制（即积极执法与被动执法）对食肉类动物丰度和群体大小在物种和群落水平上的影响。替代管理体制在保护区内创造了生态系统条件的二分法，在马拉三角区积极执行法规，维持着较低的人为干扰水平，而在塔莱克地区则被动执行法规，允许多种形式的人为干扰。我们的研究结果表明，这些替代管理体制对 11 种观察到的食肉类动物物种有不同的影响。正如预测的那样，一些物种，如非洲狮和蝠耳狐，在马拉三角区的种群密度较高，那里的法规得到积极执行。然而，其他物种，包括黑背胡狼和斑点鬣狗，在塔莱克地区的种群密度较高，那里的执法是被动的。多种潜在机制，包括行为可塑性和竞争释放，可能导致黑背胡狼和斑点鬣狗在受干扰的塔莱克地区的种群密度更高。我们的多物种建模框架表明，食肉类动物不会对管理体制做出统一的反应，而是通过不同程度地产生优势和劣势物种来塑造食肉类动物群落。一些食肉类动物物种需要积极执行法规才能得到有效的保护，而其他物种则更容易适应（在某些情况下，对宽松的管理执法和由此产生的人为干扰做出响应）。然而，高水平的人为干扰似乎对大多数食肉类动物产生了负面影响，这可能会对整个生态系统产生潜在的影响。应该采用监测食肉类动物的社区方法，因为单一物种监测可能会忽略社区内的重要变异性。
