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.

Inter‐ and intrahabitat dietary variability of chacma baboons (Papio ursinus) in South African savannas based on fecal δ13C, δ15N, and %N

“…Percentage N (reflecting crude protein content) of available browse was higher than that for grasses, and plants displayed higher N content during the wet season in both regions (Boutton et al, 1988). Mammal fecal N content mirrored the trends observed in plants, with browsing giraffe having the highest %N, grazing zebra the lowest, and impala intermediate (Grant et al, 2000;Sponheimer et al, 2003c). Seasonally, fecal %N followed changes in plants, showing a general dry to wet season increase.…”

Body temperature variation of South African antelopes in two climatically contrasting environments

“…A plausible explanation could be their different foraging niche and ability to cope with food stress compared to the wildebeest. As typical mixed feeders, the diet of eland and impala in the dry season (winter and spring) is predominantly browse (impala: Dunham, 1980;Monro, 1980;Sponheimer et al, 2003;eland: Hofmann and Stewart, 1972;Watson and Owen-Smith, 2000). Unlike grass, the quality and quantity of browse is less dependent on rainfall and therefore the forage availability and nutrient content declines less drastically between the wet and dry season (Rutherford, 1984;Owen-Smith, 1994).…”

Influence of forage preferences and habitat use on13C and15N abundance in wild caribou (Rangifer tarandus caribou) and moose (Alces alces) from Canada

“…[10,31,32] for hair; [12,15,33] for hoof; [34] for horn). Diet-keratin isotopic discrimination has been investigated on animals fed in controlled conditions or in their natural environment.…”

“…In terrestrial systems, most ecological studies using stable isotopes have been conducted in xeric or tropical ecosystems where important isotopic contrasts are found between grazing and browsing mammalian herbivores [9][10][11]. In such ecosystems, grazers consume grass and other graminoids that use the C 4 photosynthetic pathway, while browsers eat leaves of trees and shrubs that use the C 3 photosynthetic pathway.…”