BDBSA Project Metadata Detail

Survey/Project Number: 992          Total No. of Sites: 177
Survey/Project Name: Slender-billed Thornbill - North Coast Survey
Abstract: This project aims to determine the current distribution, status and habitat of Slender-billed Thornbill (St Vincent Gulf ssp) Acanthiza iredalei rosinae near Adelaide, South Australia, in part of eastern Gulf St Vincent, north to Port Parham. This project work is contracted as part of the Samphire Coast Icon Project to check on thornbill habitat-use since the earlier work, and to provide some additional background for saltmarsh restoration and impact management for the species. In addition, the species is of regional conservation significance and was one of the "focal fauna species" identified in the Metropolitan Adelaide and Northern Coastal Action Plan (MANCAP) (2009). The Slender-billed Thornbill (St Vincent Gulf ssp) (SBT) is considered Vulnerable under the National Parks and Wildlife Act 1972, and is confined to the Gulf St Vincent. It is a small inconspicuous passerine that inhabits shrublands and heath throughout southern and central Australia, and is restricted to low chenopod shrublands containing samphire species. Matthew (1994) found SBT to be confined to areas of, or immediately adjacent to, Shrubby Glasswort (Sclerostegia arbuscula) low shrubland. From banding studies (later published in Matthew 2002) he estimated a population density of 3-8 birds per hectare, providing a population estimate for rosinae of less than 10,000 individuals. Of these, about 4000 were estimated to be in the study area. The initial survey was conducted during 2014/2015 and subsequent surveys then in 2018 and 2019. Threats to this species includes grazing, lack of recruitment of population, development and climate change.
 
Start Date: 01/08/2014      End Date: 01/01/2020
Survey Type: Fauna only
   
Study Area Description: 1. Central and western Torrens Island 2. Port Gawler CP 3. Middle Beach 4. Light River 5. South of Port Prime 6. Baker Creek (S of Webb Beach) 7. Port Parham to Webb Beach 8. Clinton Conservation Park (later surveys) 9. Bald Hill Beach (Not assessed by Carpenter (2015, 2018) but reported previously by Matthew (1994). Other samphire and chenopod shrublands near the main survey sites were also assessed. In addition, several other sites with limited areas of Sclerostegia were surveyed opportunistically (St Kilda, Para River estuary, Whicker Rd wetlands, Garden Island). A limited area of potential habitat within the St Kilda saltfields was assessed south of Port Gawler Rd.
Objectives
         Vegetation: *** No vegetation survey objectives recorded
         Fauna: Refer to Abstract.
Methodology
         Vegetation: *** No vegetation methodology recorded
         Fauna: Survey conducted from Aug to Oct 2014 and in Jan 2015 along the northern coastal zone of Adelaide by Graham Carpenter and also in 2018. Areas were searched based on known distribution within the Adelaide coastal zone and key sites which should be considered with regards to assessments crown land for potential inclusion in the Bird Sanctuary and threat management. Methods Used: Past records of rosinae in the study area were collated from published and unpublished sources and reviewed. Field survey: Colour aerial photography and DEWNR coastal vegetation mapping was analysed to determine areas likely to support the habitats most likely to support rosinae, namely Sclerostegia arbuscula shrublands.Field surveys were concentrated in areas that had been mapped as being likely to support Sclerostegia shrublands. Additional information on thornbill distribution was sought from birders that regularly visit this area. The field survey was aided by the use of play-backed calls. These were played at intervals from vehicle tracks on levees (e.g. Port Gawler) or while walking through suitable habitat. This technique usually elicited a called response from any birds within up to 100 m, with some birds flying in near to the observer. It was most useful in areas with extensive dense habitat where birds were not calling and hidden in dense foliage. Other birds were heard or flushed while the observer was walking. The field survey was undertaken by one or two observers walking through suitable habitat and listening for calls or by flushing birds. Any birds seen were watched from a distance to determine if a possible nest or fledglings were nearby. Access through Sclerostegia shrubland was restricted to reduce physical damage to plants, due to the brittleness of stems. Call playback was not used due to potential impacts on nesting birds. The nest of rosinae is described well by McGilp (1925), with a decoration of white spider cocoons being a feature. (This also occurs in Brown Thornbills (P. Horton, SA Museum pers comm)). Juveniles were identified by their darker eyes and highpitched begging calls. All birds and nests were noted and locality recorded using a GPS. 2019 survey - Field surveys were conducted in six areas also by Graham Carpenter, Sam Gordon and Tom Hands, where Sclerostegia shrublands were known to have supported populations of rosinae in previous surveys, plus an additional site not previously assessed since Matthew (1994) but containing suitable habitat.

Data Distribution Rules: Public Dataset
Project Basis: Fauna : EPBC/NPWSA Threatened species targeted survey. Flora or fauna species.
Fauna : Presence and absence method
Information Authority: Adelaide and Mount Lofty Ranges Natural Resources Management (NRM) Region
Department for Environment and Heritage (BDBSA:Adelaide) - Cleland Office