Impact of predation by greater flamingos Phoenicopterus ruber on the macrofauna of two southern African lagoons

Abstract

Greater flamingos Phoenicopterus ruber were excluded from intertidal areas of one lagoon and intertidal and subtidal areas of another, both on the Namibian coast. Macrofaunal numbers increased at all exclusion sites, reaching approximately 3 times the density of control plots subtidally, and 1.5 times the control density intertidally. Only 1 species, the polychaete Diopatra neapolitana, decreased in abundance inside cages. Both intertidal sites were polychaete dominated; subtidally, ampeliscid amphipods dominated and formed dense tube-mats that covered the substrate. Despite differences in macrofaunal abundance between treatments, diversity indices were similar. Overall, P. ruber have a major effect on macrofauna at these lagoons. In their absence, physical factors may play an important role.