Seeds dispersed in dung of insectivores and herbivores in semi-arid southern Africa

We investigated the incidence of endozoochory in the semi-arid South Africa n Karoo shrubland and Kalahari savanna by dissecting and germinating seed f rom dung samples from a wide range of wild mammals and domestic livestock. Intact seeds occurred at a mean density of 1575 seeds kg(-1) in livestock a ir-dried dung and 3613 seeds kg(-1) in air-dried dung of indigenous animals . Seedlings emerged from dung at an average density of 153 kg(-1) air-dry d ung. Seeds of Aizoaceae, Mesembryanthemaceae, Chenopodiaceae and Poaceae we re abundant in the dung of wild and domestic herbivores as well as such ant - and termite-eating insectivores as aardvark (Orycteropus afer) and bat-ea red fox (Otocyon megalotis). Seeds of fleshy-fruited shrubs occurred in dun g of browsing herbivores and the bat-eared fox. Five non-indigenous weeds w ere found in the dung samples. Although the floras of the Kalahari and Karo o are considered to be largely wind and water-dispersed, endozoochory is a primary or secondary dispersal mechanism in many plant families and for man y plant life-forms. Animals dispersed seeds of many species characteristic of fertile and disturbed habitats. In Mesembryanthemaceae, a Family in whic h seeds are primarily dispersed very short distances by raindrops, endozooc hory enables occasional long-distance dispersal. (C) 2001 Academic Press.