The stratigraphy, hydrology and vegetation of the Heard Island (sub-Antarctic; 53 deg. 05'S, 73 deg. 30'E) 'pool complex' bogs are described. Spatial variation in processes that might have contributed to their formation are discussed. This community occurs where drainage has been impeded, with Callitriche antarctia being the indicator species. Particular attention is paid to the interaction of the ... vegetation, pools and animals. Surface stratigraphy, peat depth, water depth and vegetation composition were measured along transect lines. Species over abundance data of 300 quadrats were classified using a two-way indicator of species analysis program and ordinated using detrended correspondance analysis. The major factors determining vegetation composition were found to be peat depth, surface topography, and the degree and type of animal disturbance. Similarities between the pool complexes on Heard Island and bogs back in Tasmania, and northern hemisphere temperate and boreal zones appear to diminish as the density of the animals occupying this habitat increases.