Ecology of wildlife reintroduction : habitat selection of reintroduced lions (Panthera Leo) and behavioural responses of their prey

Abstract

Reintroduction is used for re-establishing species in their former ranges where they had been extirpated. In South Africa, the growth in tourism industry in recent years has resulted in rapid establishment of wildlife reserves, where the land was historically used for livestock farming. Large carnivores are often reintroduced in these reserves for conservation and tourist attractions. However, long-term monitoring on post-release behaviour that is critical for reintroduction success remains limited. The reintroduction of lions (Panthera leo) to Dinokeng Game Reserve has provided an opportunity to investigate the behaviour of reintroduced large carnivores and their impact on prey behaviour. The early post-release period is critical for reintroduced animals to learn the locations of essential resources for fitness and survival. In this study, early post-release movement of lions was investigated. Movement patterns varied greatly between individuals. Post-release dispersal from the release site was observed, but some groups returned to the area of release while others settled further away. Rates of movements differed at different times of the day and some of the lions avoided buildings while others showed a sign of habituation over time. Despite individual variations, the movement patterns started to stabilise by the end of the first season, suggesting that the animals had been exploring the environment before settlement. To understand the space use of reintroduced lions, their second and third order of habitat selections, home range utilisation and home range resource selection, respectively, were examined. Exploratory behaviour was found in space use patterns. The rates of expansion in home range sizes were the highest after release, and declined over time. Resource selection patterns showed consistent change in trends but also stabilized over time. All lions established home ranges at their release area and selected for landscape features with low topographic roughness, high prey availability and accessibility, and low human disturbance. The locations and order of release had great impact on spatial behaviour by influencing inter-group interactions. Lions avoided the home ranges of those released earlier at the same site and their selected vegetation. The presence of predators generates a “landscape of fear” in which prey adjust anti-predatory behaviour according to the levels of perceived predation risk. Intense and routine vigilance response of wildebeest (Connochaetes taurinus) and zebra (Equus quagga burchellii) to the “landscape of fear” topographies were tested in this study to assess the impact of predator reintroductions. Response was species-specific, but in general, intense vigilance increased with higher predator encounter rate, higher predator lethality and lower effectiveness of the vigilance behaviour. In contrast, routine vigilance response related more to the amount of time the animals could potentially spare when foraging under different environmental conditions. This study indicates the usefulness of monitoring animal movement and patterns of habitat selection in assessing post-release wildlife dynamics. It highlights the importance of adequate spatial planning of release sites when multiple releases are to occur, to minimise inter-group competition and maximise the reintroduction success; and the application of focal sampling of prey behaviour as indicator of the intensity of predator impact.