||Flooded areas were sampled as part of a second complete census of the Chowilla Bush Stone-curlew population. Sampling was conducted over the known extent of occurrence on the floodplain of the Chowilla and Ral Ral anabranches. The census used call playback methods to systematically cover this extent from west to east over 12 nights. Geographical sectors were used to manage identification of selected play sites (i.e. from where the call recording was played). Call playback was used to acquire a rough locational fix on individual birds. As a cryptic and nocturnal species, the Bush Stone-curlew is most frequently located by aural means. This can often be assisted by playing a recording of the call to encourage vocal responses from the birds. Call playback is a well-documented means of sampling elusive species, and has been widely used as a survey method in other Bush Stone-curlew studies (Price 2004, Gates 2001). The call playback procedure comprised a five-minute stop at each play site. The recording was played for 30 seconds, observers listened for two minutes, and the sequence once repeated. Recorded calls were projected through two speakers attached to the roof of a vehicle. The direction of any bird calls responding to the recording (`vocal responses') was estimated with a compass, and distance to the responding bird was approximated. Additional notes added by Ellen Krahnert requested by Ellen Ryan-Colton: (other previous notes have not been deleted to retain full data history - Ellen Ryan-Colton may want to alter). A report was produced detailing the distribution of Bush Stone-curlews in the Murraylands using data up until 2007. From 2007 to 2009, the same methodology (call play back for 30 seconds, listen for 2 minutes and repeat once) was used at a reduced number of sites, for up to 6 consecutive nights each month. The aim was to undertake a detectability study across different months of the year to determine the best time of year for continued population monitoring. A report is available that summarises the best detection time for Bush Stone-curlews using call play-back at those locations. Sites included those on the Calperum Floodplain (CALP01,CALP02, CALP09, CALP10, CALP11, HUNC01, HUNC05, RENY01, RENY02, RENY04, RENY05, RENY07, RENY10, RENY12) and Chowilla Floodplain (CHDET01, CHDET02, CHDET03, CHDET04, CHDET05, CHDET06, CHDET08, CHDET10) From 2010 onwards, the same metholodology (call play back for 30 seconds, listen for 2 minutes and repeat once) was used at a the detection sites above, and in winter of each year. Friends of Riverland Parks and DEWNR staff repeated the surveys over 4 nights within the same week (usually consecutive, dependent on weather).
However, due to flooding of the floodplain in 2011, and environmental regulator works, some sites were not completed in 2011 and 2012.
2010 sites were completed at Chowilla and Calperum.
2011 and 2012 sites were completed only at Chowilla, missing some due to limited access to work site of environmental regulator.
|Study Area Description:
||Murraylands Region. Playsites located at: Reny Island, Reny and Hunchee Island, Calperum - main floodplain, Coppermine Waterhole, Chowilla Island, Chowilla and Monomon Islands, Coombool Swamp, Coombool and Gum Flat, Tareena Station, Punkah Island and Tareena and Coppermine, Sedan, Mantung and Kulkyne Creek, Buly Lagoon. Opportune: Sedan, Monash, KOM, Bakara, Cooltong, Gum Flat, Chowilla Game Reserve.