abstract
Birds and seals act as agents of erosion on the coastal lowlands of sub-Antarctic Marion Island. Erosion primarily occurs where birds congregate at high densities to breed and is accentuated by the soft-foliage vegetation, easily eroded peaty substrate and wet climate. Different groups of birds 杅lying surface breeders, flying subterranean breeders and flightless penguins- each have particular erosive effects. Penguins cause most erosion and even affect bedrock. Bird activity causes slumping on sleep slopes. The erosive effect of seals is minor.