Grey Grasswren in the Bulloo Lakes system, completion report, November 2013

In order to inform property management planning for Bulloo Downs station, southwestern  Queensland, a survey to identify habitat and hotspots for Grey Grasswren Amytornis barbatus barbatus was conducted in the Bulloo Lakes wetland system during 7-1 1 October 2013. Although known to occur in south-central parts of the system, mainly south of the NSW State border, there have been few if any previous

records of Grey Grasswren from northern parts of the system. This nominate subspecies of Grey Grasswren is listed as Vulnerable under the Commonwealth EPBC Act 1999 and is considered to be declining in NSW.

The survey was funded by South West NRM Ltd and conducted by two ornithologists with extensive experience of this highly secretive bird from floodplains of southwestern Queensland and adjacent South Australia and New South Wales. Focussing on shrublands of lignum Muehlenbeckia florulenta in dried wetlands in the ar north and north-east of the Bulloo River's terminal wetlands, 38 sites were

searched. Characteristics of vegetation and substrate at each site were documented

and examples of habitat were photographed.

Grey Grasswrens were seen andlor heard at nine (9) sites within five (5) localities widely spread across the study area on Bulloo Downs. Grasswrens were detected in communities that varied in cover, height, diameter and greenness of lignum shrubs. In most cases they were found where some lignum occurred as joined clumps and commonly where short plants occupied some of the substrate. No grasswrens were detected in massive lignum clumps in and around the dried lakes; in these sites, water persists longest and once dry the ground is mostly bare. Belalie Acacia stenophylla shrubs were present at some of the sites where grasswrens were recorded. Old man saltbush Atriplex nummularia, a habitat sometimes used by Grey Grasswrens, is widespread in lowlands immediately surrounding these northern Bulloo Lakes wetlands.

The survey results increase the known extent of occurrence of the subspecies by over 600 km2 and extend its range 26 km northwards. Together with enhanced knowledge of its habitat preferences and abundance, this greatly improves its conservation prospects. Presence of the Grey Grasswren places responsibility on landholders and NRM practitioners to wisely manage its lignum swamp habitat. No

immediate conservation action has been identified. But it is recommended that suitable graded firebreaks be maintained and added, to minimise loss of habitat for Grey Grasswrens, especially around a cluster of five sites in Jerridah Channel occupied by grasswrens. Reduction of likely predation by feral cats may be desirable if cost effective control can be achieved. Recognising the preliminary scope of the

project, other recommendations call for follow-up surveys to consolidate the present findings, determine site fidelity of the grasswrens, and develop deeper understanding of their ecological requirements and threats to survival in the Bulloo Lakes system. 

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