Anthropogenic influences on spotted hyaenas in a protected area the Kruger National Park

Abstract

Human population growth generally causes carnivore declines. The rapid expansion of urban landscapes creates both biotic and abiotic changes that are known to negatively impact carnivore populations (Šálek, Drahníková & Tkadlec, 2015). Carnivores are considered particularly sensitive to human population growth and urbanisation due to persecution, large home range requirements and slow population growth (Woodroffe, 2000). This can cause local extinctions or active avoidance of humans by carnivores (Ordeñana et al., 2010; Schuette et al., 2013). However, some carnivore species are attracted to areas with high human population densities due to the benefits associated with the use of human based resources such as food and shelter. The spotted hyaena (Crocuta crocuta) is the most social of all hyaena species. Clans vary in size from three in the Kalahari up to 80 in East Africa. Spotted hyaenas typically eat prey of medium to large body size. The spotted hyaena is known for its opportunistic scavenging and the species will readily exploit anthropogenic food. In contrast to many species associated with anthropogenic food use, spotted hyaenas are large carnivores that often hunt larger prey. In this study I tested how life-history characteristics influenced visitation at known human resource sites, how the amount of anthropogenic material in scat samples varied in relation to human habitation, and how anthropogenic activity and infrastructure modified the behaviour of a large carnivore, the spotted hyena, in the Kruger National Park. I found that subadults and juveniles were the most frequent visitors at known anthropogenic sites, and I suggest that hyaenas were not visiting the anthropogenic sites in a need of food. Analysis of scats taken from the whole range of the southern section of the park showed that anthropogenic use was quite low, but also that the use was higher in the dry than in the wet season. However, anthropogenic material did not seem to have been included in hyaena diets in proportion to its availability. Instead, anthropogenic resources appear to have been utilised only by certain hyaenas or cohorts. Despite a presumed low value of anthropogenic resources, human activity and infrastructure were still altering spotted hyaena behaviour. A collared hyaena living in an area with large amounts of anthropogenic activity and infrastructure had a smaller home range that was used less evenly than another collared female living with less contact with humans. Home range size and use also exhibited seasonal variation, with larger areas used in the dry season. Spotted hyaenas inhabiting areas with higher human activity and infrastructure exhibited lower social network density and longer path lengths than those living away from human activity. However, my results did not fully follow those predicted by variations in resource abundance. We predicted that hyaena clans in areas with denser infrastructure and more human activity would show less group cohesiveness and hence both less dense and less complex social networks, caused by a greater access to anthropogenic food and therefore a decreased need for group related foraging.To conclude, my results suggests that anthropogenic resources in the Kruger National Park were of limited nutritional value for or not preferred by spotted hyaenas, but that they were still utilised and influenced spotted hyaena space use and social interactions. These observations are perplexing, and I suggest that further work is needed to improve our understanding of the impact of human activity and infrastructure inside protected areas on native wildlife populations.