Forage selection of African buffalo through the late dry season in the Satara region of the Kruger National Park

Abstract

Forage selection by buffalo and the contribution of grass species to buffalo diet were investigated in the granite and basalt landscapes in the Kruger National Park during the late dry season, between July and October in 2002. Two buffalo herds were selected for observation, occupying each of the landscapes. Data on forage selection and dietary contribution were collected by backtracking along the foraging pathways and identifying grazed and not grazed tufts in feeding quadrats. The percentage of green leaves, tuft height and number of stems of each tuft were recorded. Four fixed transects were placed across the catena in each landscape and greenness retention was measured by checking for green leaves in quadrats.<br><br> Panicum maximum, Panicum coloratum, Cenchrus ciliaris, Heteropogon contortus and Digitaria eriantha were favoured grass species by buffalo. Urochloa mosambicensis, Themeda triandra, Eragrostis superba and Bothriochloa insculpta were classified as intermediate, whereas Cymbopogon spp. Setaria spp., Pogonarthria squarrosa and Aristida congesta barbicolis were neglected. The acceptance frequency of grass species increased with the progress of the dry season, but only D. eriantha, U. mosambicensis, E. superba and B. insculpta recorded significant increases in acceptance between consecutive periods. P. maximum, T. triandra and D. eriantha contributed more to the diet of the herd on the granites than to the diet of the herd on the basalts, whereas P. coloratum, U. mosambicensis and C. ciliaris contributed more to the diet of the herd on the basalts than to the diet of the herd on the granites. Buffalo selected for grass species offering a higher percentage of green leaves and intermediate! height. Selection for grass species by buffalo did not differ significantly between the two landscapes.<br><br> Landscapes did not differ significantly in the proportions of quadrats retaining green leaves during the dry season. Grass in bottomlands was greener than grass in midslopes or uplands. In July, most feeding sites were located in bottomlands, but with the progress of the dry season buffalo increased the utilization of midslopes and uplands.