The influence of apex predators and humans on the occurrence and temporal activity patterns of crop-raiding mammals in southwestern Ethiopia
Summary
Human activities, such as land-use change, are altering landscapes at the expense of wildlife habitat, resulting in a global loss of biodiversity. These changes are particularly concerning in the tropics, because this region houses over half of the Earth’s biodiversity. One of the most threatened regions is southwestern Ethiopia, as part of the Eastern Afromontane biodiversity hotspot, where many biodiverse Afromontane forest areas have been converted to agricultural land. Here, the local human population is highly dependent on the natural resources that are provided by the forests. In turn, mammals raid crops in the agricultural land outside of the forests, which is a critical disservice for humans. In order to both conserve crop-raiding mammals and improve human-wildlife coexistence, a better understanding is needed of the spatial and temporal behavior of these crop-raiders in relation to their environment, and apex predator and human disturbance. Little is known about the role of humans on these interactions, particularly in the tropics. This study explores these research gaps and aims at understanding the spatiotemporal activity patterns of two crop-raiding mammals, the bushpig and common warthog, and the leopard, which is the apex predator in the region.Using data from 92 camera traps over 10,894 camera days, generalized linear mixed models (GLMMs) were built for each species to model their spatial activity, as occurrence, in relation to their environment (using forest cover data), apex predator presence, and human presence. Their temporal activity patterns, in relation to human and leopard presence, are modelled using kernel density functions.GLMMs outcomes showed that there was only one significant relationship between the mammal occurrences and the explanatory variables, which was the positive influence of forest cover on warthog and leopard occurrences. The temporal activity patterns suggest that humans likely influenced the temporal activity of the three mammals, whereas an influence of leopards was again not observed. The latter indicates that the top-down control of leopards on these species was absent. A potential top-down influence of humans was only observed in the temporal activity of the three target species, which suggests that they may separate themselves in time rather than space from human disturbances in southwestern Ethiopia. I discuss the theoretical and practical implications of these results for conservation efforts to improve human-wildlife coexistence and maintain biodiversity, with particular focus on the target species. There may be different mechanisms driving the observed outcomes, which underlines the necessity for future research.