Small mammal pollination in Protea Witzenbergiana

Protea witzenbergiana possesses some features common to that of therophilous Proteas in the Cape Floristic Region, such as a cup-shaped, downwards-hanging inflorescence surrounded by red involucral bracts, which emits a yeasty, musky odour. The flowering season occurs in the winter and the plants occur in small, localized and isolated stands in the Witzenberg fynbos. However, the species has never been investigated as to whether it is pollinated by small mammals. This study investigated whether the plant is rodent-pollinated, and if so to what extent by various species. Fieldwork was carried out over three days of live trapping, during and after the flowering season. Exclosure experiments were set up in order to assess seed set. Mammal droppings were collected, processed and pollen grains were counted. All small mammal species excepting one (Otomys irroratus) contained pollen grains in their faeces. Oendromus melanotis, Mus minutoides and Aethomys namaquensis were found to be the most important pollinators. The small mammal community showed a distinct change in size and composition after flowering season had ended, suggesting that the availability of nectar resources may be an important food supply to small mammals in the area. Implications of these findings could be relevant for conservation and co-evolutionary studies