The swift parrot (Lathamus discolor, Psittacidae) is an endangered, austral migrant that inhabits forests and woodlands of south-eastern Australia. With a small population size (2500 birds), broad winter distribution (1 250 000 km2) and often cryptic nature, the swift parrot is a challenging species to study. In autumn they migrate north from their Tasmanian breeding grounds in search of suitable food resources throughout their winter range on mainland Australia. They are therefore dependent on a combination of suitable wintering, migration and breeding habitats. Although they spend a large proportion of their lives within winter habitats, the spatial and temporal dynamics of habitat use in this part of their range is poorly understood. This thesis aims to provide a greater understanding of large-scale winter habitat use by swift parrots, in both historic and current contexts, and provide a basis for future conservation management. ...¶ During drought swift parrot abundance was significantly correlated with rainfall, whereby most of the population either concentrated in a few regions or migrated longer distances (up to 1000km) to drought refuges in wetter coastal areas. However, swift parrot abundance was not associated with specific climate variables during years of average to high rainfall throughout most of their range. Instead they appeared to prefer habitats within particular regions. Importantly this study emphasises that conservation measures need to be implemented throughout the distribution of migratory species, including drought refuge habitats and areas outside conservation reserves.