Ecological trap in the buffer zone of a protected area: Effects of indirect anthropogenic mortality on the African wild dog Lycaon pictus

Abstract

Because of the large home range requirements of wide-ranging carnivores, protected areas are often too small to maintain large populations. Consequently these carnivores regularly move outside protected areas, where they are likely to be exposed to anthropogenic mortality. We used data from 15 packs of radio-collared African wild dogs Lycaon pictus to examine the level of anthropogenic mortality African wild dogs experience around Hwange National Park, Zimbabwe, and tried to determine whether the buffer zone outside the Park acts as an 'ecological trap'. Over time, study packs moved their territories closer to or beyond the Park border. With the movement of territories into the buffer zone outside the Park, African wild dogs experienced an increasing level of anthropogenic mortality. Although larger litters were born outside the Park, mortality exceeded natality. Densities of the African wild dog in the study area were low and territories for given pack sizes were smaller outside the Park. Hence, the movement of packs outside the Park does not appear to be density related and the buffer zone is therefore unlikely to function as a classic sink. Favourable ecological conditions indicate that the buffer zone outside the Park is likely to serve as an ecological trap, with fitness-enhancing factors attracting African wild dogs outside the Park, where they are incapable of perceiving the higher mortality risk associated with mostly indirect anthropogenic causes. As far as we know this is one of the first studies describing an ecological trap for mammals. © Fauna & Flora International 2013.