Comparative foraging behaviour and associated energetics of impala and blesbok.

Published online
16 Dec 1986
Content type
Journal article
Journal title
Journal of Applied Ecology

Klein, D. R. & Fairall, N.

Publication language
Africa South of Sahara & South Africa


Field studies were caried out at 3 locations in South Africa to compare the lifestyles of impala (Aepyceros melampus melampus) and blesbok (Damaliscus dorcas phillipsi). The vegetation at Derdepoort was mainly grassland, dominant grasses included Imperata cylindrica, Themeda triandra, Heteropogon contortus, Hyparrhenia hirta, Aristida bipartita and Setaria spp. At the 2nd site in the Kruger National Park, Panicum spp., Digitaria spp. and Aristida spp. were present, while at S.A. Lombard Nature Reserve, Cymbopogon plurinodis and Themeda triandra with interspersions of Eragrostis spp., Aristida spp. Sporobolus spp. and Enneapogon scoparius were found. Blesbok had a shorter daily feeding time (49.9% grazing) than impala (57.7% grazing + 16.1% browsing) and fed almost exclusively on graminoids while the diet of the impala was more variable but included a high proportion of dicotyledons. Faecal CP content reflected this difference and was higher in impala than blesbok. Results of daily activity patterns, gut morphology, food habits and water turnover rates of the 2 species are discussed. It was concluded that the life strategy of blesbok emphasizes energy conservation while impala maintain a more energetically costly lifestyle. Blesbok adjust energy expenditure to compensate for seasonal variations in diet quality. Impala have a greater dependence on high-quality food obtained by selective feeding and seasonal diet flexibility.

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