Changes in elephant conservation management promote density-dependent habitat selection in the Kruger National Park

Abstract

In conservation, adaptive management relies on the assessment of past actions to improve conservation efficiencies in the future. Conservation management approaches for African elephants have recently changed, however little has been done to assess the effectiveness of these changes. This is a major shortcoming as elephants (and their management) have a considerable influence on other savanna species. Traditionally, the management of elephants has focused on artificially manipulating numbers through culling, water supplementation and fencing. Lately, and specifically in the Kruger National Park, the focus has progressed to promoting ecological processes that may naturally regulate elephant populations. Density‐dependent habitat selection – suggestive of competition for resources – is fundamental in stimulating the regulatory processes that managers expect to promote. In this paper, we evaluated how effective the changes in Kruger's elephant management approach had been in promoting density‐dependent habitat selection. We used 15 years of helicopter‐based surveys and resource selection functions to test our primary prediction that an increase in population density following the cessation of culling generalized dry‐season habitat selection by female elephants in Kruger (i.e. decreased selection of high‐quality habitat and increased selection of lower quality habitat). We found that as densities increased, female occupancy of the Park rose and dry season selection of highly wooded areas, which provide crucial resources for elephant survival and reproduction, weakened. Conversely, density had little effect on the selection of rivers. Rather, high dry‐season rainfall allowed female elephants to select areas farther from permanent water, potentially alleviating normal dry‐season foraging restrictions. Our novel identification of density‐dependent habitat selection for elephants suggests that the change in conservation management in Kruger was effective in promoting a potential driver of population regulation. We suggest that ecological principles continue to provide an effective framework for scientific evaluation and elephant conservation management in Kruger and beyond.