Forage selection by African buffalo in the late dry season in two landscapes

Forage selection by buffalo and the contribution of grass species to buffalo diet were investigated by comparing two herds occupying granite and basalt landscapes in the Kruger National Park. Observations spanned the late dry season, from July to October 2002. Grass remained greener in bottomlands than in midslopes or uplands within each landscape, but greenness was not significantly different between the basalt and granite land-scapes. The favoured grass species remaining highly acceptable to buffalo throughout the late dry season included Panicum maximum, Panicum coloratum, Cenchrus ciliaris and Heteropogon contortus. However, the dietary contribution by these species declined with the progress of the dry season owing to a reduction in the available forage that they retained. The acceptance frequency as well as the dietary contribution of Urochloa mosambicensis, Digitaria eriantha and Eragrostis superba increased over time, while Bothriochloa spp. became moderately acceptable at the end of the dry season in October. Themeda triandra, a species highly rated as forage for cattle, appeared intermediate in its acceptability to buffalo and made a relatively small dietary contribution in both landscapes. In accordance with foraging theory, buffalo expanded the range of grass species accepted, changed the proportions of grass species in their diet and shifted their grazing locations within the landscape