Dusky Gerygone

Morphology

The Dusky Gerygone is 10-13 cm, with the upper parts grey brown, and tinged with olive on the head and back. It has an indistinct pale line from the bill, extending above the eye. The under parts are greyish white, with a black bill and shiny black legs.

Evolution

The Dusky Gerygone belongs to the Family Acanthizidae, also known as the Australian warblers, which includes the gerygones, thornbills and scrubwrens. They are found in Indonesia, Australia, New Zealand and the south west Pacific. The Gerygone Warblers are a very recently evolved group, with molecular analyses suggesting many species arose within the Pliocene (approximately 5.33 million to 2.58 million years before present) and Pleistocene (2,588,000 to 11,700 years before present). The Dusky Gerygone is part of a very recently speciated group, including Gerygone flavolateralis, G. fusca, G. levigaster, G. ruficollis, G. igata, and G. modesta. These species are found across islands in the Pacific, in New Zealand and Australia. In Western Australia, areas where mangroves do not grow break up the distribution of the Dusky Gerygone. These areas have been tested as long-term barriers to dispersal, and the possibility for populations to be distinct on either side of these barriers.

Behaviour

The Dusky Gerygone can be found foraging among mangroves.

Method of reproduction

Sexual

Habitat

Terrestrial

The Dusky Gerygone is restricted to mangrove habitat.

Distribution

The Dusky Gerygone is endemic to Western Australia, found in the mangrove habitat from Shark Bay to Kunmunya. Its distribution is broken up by the presence and absence of mangrove habitat, to which it is restricted. Major breaks in its distribution include eighty-mile beach, located between the Pilbara and Kimberley regions.