Detecting predators and locating competitors while foraging: an experimental study of a medium-sized herbivore in an African savanna

Vigilance allows individuals to escape from predators, but it also reduces time for other activities which determine fitness, in particular resource acquisition. The principles determining how prey trade time between the detection of predators and food acquisition are not fully understood, particularly in herbivores because of many potential confounding factors (such as group size), and the ability of these animals to be vigilant while handling food. We designed a fertilization experiment to manipulate the quality of resources, and compared awareness (distinguishing apprehensive foraging and vigilance) of wild impalas (Aepyceros melampus) foraging on patches of different grass height and quality in a wilderness area with a full community of predators. While handling food, these animals can allocate time to other functions. The impalas were aware of their environment less often when on good food patches and when the grass was short. The animals spent more time in apprehensive foraging when grass was tall, and no other variable affected apprehensive behavior. The probability of exhibiting a vigilance posture decreased with group size. The interaction between grass height and patch enrichment also affected the time spent in vigilance, suggesting that resource quality was the main driver when visibility is good, and the risk of predation the main driver when the risk is high. We discuss various possible mechanisms underlying the perception of predation risk: foraging strategy, opportunities for scrounging, and inter-individual interference. Overall, this experiment shows that improving patch quality modifies the trade-off between vigilance and foraging in favor of feeding, but vigilance remains ultimately driven by the visibility of predators by foragers within their feeding patches

Bird tolerance to humans in open tropical ecosystems

AbstractAnimal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene.</jats:p

Illegal hunting and protected areas: Tourist perceptions on wild animal poisoning in Hwange National Park, Zimbabwe

Tourists visiting protected areas for leisure often have perceptions based on pre-conceived knowledge and awareness about wildlife conservation obtained through various media. However, these perceptions are rarely tapped into for management and policy reviews. To understand tourists' perceptions on conservation, we surveyed 76 tourists in Hwange National Park, Zimbabwe, using a questionnaire administered through convenience sampling. Our results showed significant differences (Chi-square = 11.8; df = 1; p = 0.001) between tourists who acknowledged awareness (69.7%, n = 53) of the use of chemical poisoning to kill wild animals prior to their visit and those who were unaware (30.3%, n = 23). We conclude that some tourists are concerned about the state of wildlife conservation at their destinations of choice. We recommend the consideration of tourists concerns in conservation policies and strategies

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(Published By University of Alabama

Drivers of diurnal rest site selection by spotted hyaenas

Rest sites are key locations to many animals but their selection has been poorly studied in large carnivores. We investigated seasonal diurnal rest site selection by spotted hyaenas (Crocuta crocuta) in Hwange National Park, Zimbabwe. We assessed the effects on hyaena diurnal rest site selection of (i) distance to the nearest waterhole, as waterholes can be considered prey hotspots in the study ecosystem, (ii) habitat type and vegetation characteristics, in particular visibility as it influences detection risk and shade for thermoregulation, (iii) location within the core territory of their main competitor/predator, the African lion (Panthera leo), where encounter risk would be higher, (iv) distance to the closest lion, and (iv) distance to the nearest road as they can facilitate travelling by carnivores. We defined rest sites as midday locations of hyaenas equipped with GPS collars. Hyaenas preferred to rest in woodland areas with low visibility, close to roads and far from a lion. Distance to the nearest waterhole and location within lion core territory did not affect hyaena rest site selection. Overall, our study points to the combined importance of the structure of the vegetation (providing safety and shade), the availability of roads (to move through and exploit this bushed environment), and the avoidance of proximity to lions

Drivers of diurnal rest site selection by spotted hyaenas

International audienc

Bird tolerance to humans in open tropical ecosystems

Animal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene