Serengeti ungulates: feeding selectivity influences the effectiveness of plant defense guilds.

Association of Themeda triandra, a palatable grass species, with less palatable plants protected it from grazing by two comparatively unselective herbivores, wildebeest and African buffalo. Grazing on T. triandra by two more selective herbivores, Thomson's gazelle and zebra, was not related to the relative abundance of less palatable plants. The differential effectiveness of plant defense guilds against different ungulates may contribute to the high species diversity of the East African grazer fauna.