Diets of impala from Kruger National Park: evidence from stable carbon isotopes

Abstract

Impala are known to exhibit dietary flexibility, relying primarily on browse in some areas and graze in others. In this study we use stable isotope analysis of faeces and hair to examine the diets of Impala in Kruger National Park. As expected, the data show that Impala are mixed-feeders and highly distinct from grazing buffalo and browsing kudu. Moreover, Impala, Buffalo, and Kudu faeces contain 2.1 %, 1.4 %, and 2.9 % nitrogen respectively, suggesting that Impala diets are of intermediate quality. There are also marked differences between Impala populations in the northern and southern regions of the park. The northern Impala graze less than their southern counterparts. This difference probably reflects decreased availability of herbaceous forage in the mopane-dominated north. Males and females also have different diets, with males grazing more than females.