Donkeys as livestock guardians against predators in an African savanna

Human population growth has led to increasing conflicts with wildlife, with actual or perceived livestock predation by carnivores being a primary source of conflict. Subsequently many carnivore populations on landscapes with livestock production are threatened through retaliatory killing. A common method to prevent such conflict is using guardian animals with the livestock to protect them from predators. While the effectiveness of guardian dogs (Canis lupus familiaris) has been extensively studied and demonstrated, dogs are primarily used for small stock, can be expensive to source and maintain, and will sometimes impact non-target wildlife species. Therefore, other guardian animals, such as donkeys (Equus africanus asinus), may provide alternative protection, although this has rarely been tested empirically. We studied the impact of donkeys and their effectiveness in deterring three carnivore species: leopard (Panthera pardus), brown hyena (Parahyaena brunnea), and black-backed jackal (Lupulella mesomelas). The donkeys were placed alongside vulnerable cattle (calves) in a Southern African savanna (Namibia) used as rangeland, and we monitored both these predator and livestock species using camera traps over a span of ten months to derive relative abundance, co-occurrence and activity patterns metrics. We conducted the study using 61 camera traps across 104 control-phase days (no donkeys) and 92 treatment-phase days (donkeys present) spanning wet and dry seasons. Depredation levels were low in the absence of donkeys, whereas no calves were depredated when donkeys were placed with livestock. Carnivores and livestock had similar relative abundances, co-occurrence, and activity patterns before and after the addition of donkeys. Leopards changed their land use pattern in the second phase of the study when the donkeys were added, however this could also be attributed to changing prey densities and not donkey presence alone. A significant decline in predator occurrences following cattle presence, determined through event frequencies within a defined cutoff time window was observed following the addition of donkeys, and could be the reason no depredation was observed. This suggests that donkeys can work as an effective guardian animal to reduce loss of cattle calves, however, due to camera traps not detecting the fine scale interactions that may have occurred between donkeys and carnivores, monitoring with GPS tracking technology would enable refined understanding of donkey effectiveness as guardian animals.