The distinguishing feature of Africa’s large mammal fauna is its diversity of grazing ruminants. Relative security from predation contributes importantly to niche separation among herbivore species of similar size, coupled with distinctions in grass height grazed. Grazers present on other continents prior to the late Pleistocene extinctions tended to be very large and mostly non-ruminants. Although some deer consume much grass, none is specialised in dentition and digestive anatomy for an exclusively grass diet. This is perhaps because the C3 grasses prevalent in higher northern latitudes are more readily digested than the C4 grasses prevalent through tropical and subtropical Africa, especially during the season of plant dormancy. Grasses growing under higher rainfall elsewhere in the tropics seemingly require hindgut fermentation to handle their high fibre contents.