The feeding ecology of the African wild dog Lycaon pictus in Hluhluwe- Umfolozi Park.
The small population size of wild dog Lycaon pictus (10) in Hluhluwe-Umfolozi Park (HUP) and the decline in their numbers since 1992, has caused concern for their survival and consideration of further introductions. In the light of many failed wild dog relocation and reintroduction programmes, this study contributes towards an understanding of the ecology of the HUP wild dog pack. Wild dog prey preference was determined from scat analysis and personal observations, and their potential impact on the primary prey species was modelled. The choice of physical habitat features by wild dog and their ranging behaviour within the Park were correlated with the distribution of their primary prey and other predators. To determine the susceptibility of prey to predation in three reserves with different predator diversities and densities, prey vigilance and prey response to playback recordings of predator calls were recorded. The results showed that wild dog preference for females, adult nyala Tragelaphus angasi and juvenile impala Aepyceros melampus, was a function of prey abundance, profitability calculated using a diet choice model, and ease of capture. Based on the overall lack of association of wild dog and their primary prey species and predators, and the overall lack of similarity of wild dog and prey choice of physical habitat features, predator presence was the most important determinant of wild dog ranging behaviour. Prey vigilance differed significantly between reserves and was inversely correlated with predator density. Prey response to predator calls did not differ significantly between reserves but prey did, however, react sooner to those calls unfamiliar to them. Nyala were more vigilant and responded sooner to playbacks than impala suggesting that nyala may experience greater levels of predation pressure. There was no evidence to suggest that the prey preference, habitat preference and ranging behaviour of the wild dog were influenced by the susceptibility of prey to predation. Models of prey population dynamics determined that although the introduction of an additional wild dog pack would result in a reduction of current prey population growth rates and an increase in prey population extinction probabilities, their predicted impact would be slight. Since emigration and population viability were identified as the primary causes of the HUP wild dog population decline, the introduction of two groups of wild dog individuals into Hluhluwe was suggested to boost population numbers and stimulate breeding and dispersal within the Park. The importance of future monitoring and proactive management was stressed to ensure the survival of this valuable species in the Park.