Cockatoos are distinctly Australasian both in their origins and in their present-day distributions. Twelve of the nineteen species currently recognised occur on the Australian continent with the remaining seven scattered through the islands to the north. For centuries these large showy birds have been popular as pets in Europe and yet, until fairly recently, little has been known about how they lived in their wild state. Galahas (Eolophus roeicapillus) are the commonest of the cockatoos (acatuinae) and one of the few indigenous species that have thrived throughout European settlements in Australia. Since the First Fleet landed at Botany Bay in 1788 many changes have taken place, and are still proceeding, that have had a massive effect on the fauna and flora of the continent. These changes have enabled Galahs, hitherto confined to within flying distance of tree-lined water-courses, not only to expand int the rangelands away from the rivers but also to invade the newly created wheatlands with their abundance of food suitable for granivorous birds. This monograph covers the Galah from top to tail, its habits and home, its behavior and how it lives, and conflicts, with its human neighbours.