The dispersal of African Acacia seeds in the presence and absence of large mammalian herbivores and ostriches was assessed in a savanna ecosystem in South Africa. In the absence of large herbivores, A. tortilis and A. nilotica pods were mainly dispersed in the shade, directly beneath the tree crown and seeds remained in pods for over 18 months. In the presence of large herbivores, A. tortilis, A. nilotica and A. karroo seeds were freed from pods and were dispersed into open, non-shaded habitats. Impala dispersed most A. tortilis seeds (18,900 ha−1), giraffe most A. nilotica seeds (1060 ha−1) and giraffe and kudu most A. karroo seeds (452 and 448 ha−1, respectively). Seedling survival in dung in open environments may exceed that of seedlings in soil shaded beneath the tree crown. It appears that seed dispersal by large herbivores may be advantageous to future seedling recruitment.
