An expansion of the range of the Brown Gerygone in Victoria, 1977–2009

Abstract

The Victorian distribution of the Brown Gerygone Gerygone mouki was previously thought to include only East Gippsland. Since the late 1970s, this species has been recorded at an increasing number of sites to the west, between East Gippsland and Melbourne. Throughout this period and region, nesting has also been noted but with breeding success uncertain. Brown Gerygones have been recorded in increasing numbers and in most months of the year, suggesting that they are probably now resident well to the west of their historical range in Victoria (i.e. East Gippsland). The habitats used by the Gerygones in the newly occupied range are similar to those used in East Gippsland but may differ in floristic composition, structure and naturalness. Reasons for and mechanisms of this species’ range extension are unclear and would be worthy of further research.