SUMMARYSchodde, R., I. J. Mason, M. L. Dudzinski and J. L. McKean. 1980. Variation in the Striated HeronButorides striatusin Australasia. Emu 80: 203–212.Some populations ofButorides striatusare dimorphic. Rufous birds, which predominate over grey only in coastal midwestern Australia, appear to be morphs in which phaeomelanin replaces eumelanin in greater than usual concentrations. In normally pigmented (grey) forms there is geographical variation in depth of colour and in size. Apart from the usual trend for northern populations to be smaller than those farther south, variation is irregular and of the chequer-board pattern: populations in eastern Australia and the Solomon Islands are large and dark, those from western New Guinea to the Moluccas small and dark and those in north-western Australia, south-eastern New Guinea and the Meervlakte of northern New Guinea small and pale; populations of the second and third group intergrade in the Trans-Fly of southern New Guinea. Thus, it is difficult to trace geographical relations and routes of dispersal in the region; the patchwork variation in colour is thought to have resulted from random fixation in small founding populations.The following subspecies are accepted:stagnatilisin coastal mid- and north-western Australia east to the Gulf of Carpentaria;macrorhynchusin coastal eastern Australia north to Cape York Peninsula;flyensisin coastal southeastern New Guinea;moluccarumin western New Guinea and adjacent islands west to the Moluccas;idenburgiin the Meervlakte of north-western New Guinea; andsolomonensisin the Solomon Islands and New Ireland.