Resource partitioning between black-backed jackal and brown hyeana in Waterberg Biosphere Reserve, South Africa

Understanding resource partitioning by predators is important for understanding coexistence patterns, with this becoming more relevant as historical food webs are altered through human impacts. Using scat analysis, we investigated the diet overlap of two sympatric meso-carnviores, the black-backed jackal Canis mesomelas and brown hyaena Hyaena brunnea, in Waterberg Biosphere Reserve, South Africa. Scats (n = 30 jackal, 42 brown hyaena) were collected in April 2012 from game and livestock farms. When comparing main prey categories (medium-large mammal, small mammal, fruit, invertebrate, reptile, and bird) we found little difference in diets, with both carnivores consuming predominantly medium-large mammals (10-100kg). Bushbuck Tragelaphus scriptus was the most commonly consumed large mammal species for both predators. Jackal and brown hyaena had, on average, 1.3 and 1.4 main prey categories per scat respectively which resulted in diet diversities of 3.9 for jackal and 2.5 for brown hyaena. Only jackal consumed livestock (which may have been scavenged), albeit in small amounts (< 5% frequency of occurrence). The high level of resource overlap was consistent with previous jackal–brown hyaena resource partitioning studies. Across a range of studies, resource overlap was higher when apex predator densities were lower. Thus, lower apex predator densities may restrict brown hyaena populations through the lack of carrion. At these lower brown hyaena densities, large mammal carrion, which brown hyaena rely on, may persist for longer. This persistence may enable jackals to increase their consumption of larger mammals, thereby reducing their reliance on rodents and small-medium sized mammals. Our results support the prediction that lower apex predator densities allow jackals to consume more medium to large mammals. However, diet overlap is only one of many niche axes that can assist in species co-occurrence, and further work is required to understand how jackal and brown hyaena interact at spatial, temporal and behavioural scales