Browsing by Subject "Risk effects"

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    Living with lions: spatiotemporal aspects of coexistence in savanna carnivores
    (2014-07) Swanson, Alexandra Burchard
    Top predators can suppress their smaller guild members and this can have profound consequences that cascade throughout the larger community. Suppression is mediated primarily through interference competition: (a) direct aggressive interactions, and (b) behavioral avoidance by mesopredators to minimize risks of encountering top predators. These avoidance responses can be costly, especially when they result in large-scale displacement that reduces access of the subordinate species to resources. However, fine-scale avoidance strategies may promote mesopredator persistence by minimizing risk without costly large-scale displacement. This dissertation explores the role of behavioral avoidance in driving intraguild predator dynamics. Specifically, I examine how African lions affect spotted hyenas, cheetahs, and African wild dogs in Serengeti National Park, Tanzania. Long-term lion monitoring by the Serengeti Lion Project provides a high-resolution understanding of how lions interact with each other and the landscape; I deployed a large-scale camera trapping survey to collect fine-scale spatial data on the broader carnivore community. Chapter 1 reveals that although lions displace African wild dogs from the landscape and suppress their populations, cheetahs persist with lions through space and time. Chapter 2 validates the camera trapping survey designed to study fine-scale carnivore avoidance and highlights the broad utility of citizen science for similar ecological projects. Chapter 3 applies the camera trapping survey to reveal that fine-scale avoidance does not always translate into costly spatial displacement for subordinate species. Together, these chapters identify large-scale displacement as a key driver of mesopredator suppression and fine-scale avoidance as a key mechanism for mesopredator persistence. This dissertation further establishes new methods to continue exploring community dynamics for long-lived, wide-ranging species.