Grey Grasswren

The grey grasswren occupies a restrictive area of arid inland floodplains of central Australia. Sightings have occurred at the Bulloo Overflow in the New South Wales/Queensland border area, lower Cooper Creek, along the Kallakoopah anabranch of the Diamantina River and the overflow areas of lakes Machattie, Koolivoo and Mipea on Eyre Creek in South Australia. These birds frequent mainly floodplains of the above systems which contain areas dominated by lignum and cane grass on major drainage lines between resident sand dunes. In some swampy areas, a dense understory of spike-rush, channel millet, and sedges are present. The grey grasswren has also been known to occupy open vegetative areas well beyond the lignum swamps which are less subject to inundation during flood events. It appears that in drought years the grey grasswren occupies tall dense lignum as a refuse while in normal years it prefers other habitats. Hardy recorded significantly more captures in declared drought years than in normal years. During 2011, an extensive grey grasswren survey was conducted at Frome Swamp in New South Wales which had recently experienced substantial rainfall and resultant lignum and cane grass growth. Despite the use of exhaustive surveys using mist netting, playback, vocal and visual methods, no grey grasswrens were located. This result could suggest that the species may be nomadic, an observation previously made by Hardy arising from his surveys in 2002 and 2003 at another location.

The grey grasswren is listed as threatened under the national Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act); it is listed as endangered under the Biodiversity Conservation Act 2016 in New South Wales and in Queensland under the Nature Conservation Act 1992, while the South Australian National Parks and Wildlife Act 1972 lists the species as rare. The IUCN Red List rates it as a species of least concern.