Résumé
1. Conflict between people and large carnivores is an urgent conservation issue world-wide. Understanding the underlying ecological drivers of livestock depredation by large carnivores is greatly needed.
2. We studied the spatial, foraging and behavioural ecology of African lions Panthera leo in the Botswana Makgadikgadi ecosystem. This ecosystem comprises a protected area, characterized by high seasonal fluctuation in wild prey abundance, and adjacent lands, which are used for livestock grazing and characterized by stable livestock abundance, but also a risk of anthropogenic mortality.
3. Makgadikgadi lions preferentially preyed upon migratory wild herbivores when they were present; however, data from GPS (Global Positioning System) radiocollared lions revealed that the majority of the study lions did not follow the migratory herds but remained resident at one or other border of the park and switched to livestock (abundant and readily available), and to a lesser extent resident wild herbivores (relatively scarce), in periods of migratory wild herbivore scarcity.
4. Resident lions' use of space differed between periods of wild prey abundance and scarcity. These changes were likely to increase the frequency of encounter with their primary prey in periods of primary prey abundance and with livestock in periods of primary prey scarcity.
5. The risk of conflict with humans was a major driver of lion ecology in the human-dominated landscape surrounding the protected area. Resident lions generally avoided the close vicinity of cattle-posts. When they used such areas, they avoided temporal overlap with periods that humans were most active and travelled at high speed reducing the time spent in these areas.
6. Synthesis and applications. This study suggests that lions balance the benefits of accessing livestock with the costs associated with livestock raiding. Hence, reduction in livestock availability through effective livestock husbandry in periods of wild prey scarcity should lead to reduced conflict.