Predators of similar size often compete over prey. In semi-arid ecosystems
where water is a limiting resource, prey availability can be affected by water
distribution, which further increases resource competition and exacerbate conflict
among predators. This can have implications for carnivore dietary competition.
Hence, we evaluated the dynamics of food resource competition between African
wild dogs and four competing predators (cheetahs, leopards, lions and spotted
hyaenas) in different seasons and across areas with different waterhole densities
in Hwange National Park, Zimbabwe. We used the frequency of occurrence of prey
items found in predators’ scats to analyse diet composition, overlap and prey
preference. For most predators, kudu was most frequently consumed and
preferred. Low and medium water-dependent prey (medium and small-sized) were
mostly consumed by wild dogs, leopards and cheetahs. Wild dog diet overlap was
high with all predators, particularly with hyaenas and lions. There were no seasonal
differences in the predators diet. The diet overlap of wild dogs with lions was
highest in the low waterhole density area, and wild dog diet composition did not
differ significantly from the diet of lions and hyaenas. In the low waterhole density
area, wild dogs and hyaenas broadened their niche breadth, and predators diet
had a higher proportion of low water-dependent prey. A low density of waterholes
increased food resource competition. However, high density of waterholes, where
there is more prey availability, can increase the aggregation and density of
predators, and hence, increase the risks involved in interspecific competition on
wild dogs. To reduce food resource competition on wild dogs, we propose to conserve larger-bodied prey that are less dependent on water (e.g. kudu,
reedbuck, eland, gemsbok). As the use of water pumping is common practice, we
propose maintaining water management heterogeneity where prey which is less
dependent on water can also thrive.