commence-to-flow for anabranch channels (Commonwealth of Australia 2015). Commence-to-flow heights were recorded to the nearest vertical metre. Snag data were obtained from the NSW DPI Fisheries that had been collected for the Fish and Flows in the Northern Basin Project in 2015 (NSW DPI 2015). The height above the current water level was recorded using a similar method as that used for benches and anabranches. As part of the Fish and Flows in the Northern Basin Project snags were classified into four grades of complexity (Figure D1). The vertical commence-to-flow heights of individual habitats above the current water level at the time of field survey were converted to a gauged height at the nearest river flow gauge. Benches and anabranches upstream of the Warrego River confluence were linked to the Weir 19A (NSW 425037) gauge upstream of the Selected Area, while benches and anabranches downstream of the confluence were linked to the gauging station at Louth (NSW425004) (Figure D3). Snags for the entire reach of the Darling River within the Selected Area were linked to the Weir 19A gauge only. These gauges were chosen as they best reflected the hydrology of these sections of the Darling River. However, final commence-to-flow discharges were reported at the Bourke Town (NSW 425003) gauging station as it has a more comprehensive flow record. In order to do this, relationships between the Louth and Weir 19A
Grazing ducks and geese plumed whistling-duck 8 25 Migratory Charadriiform shorebirds common sandpiperCJ 1 25 wood sandpiperCJR 1 25 Piscivores Australasian darter 5 1 50 Australian pelican 26 11 1 75 Eastern great egretJ 1 25 hoary-headed grebe 5 25 pied cormorant 3 25 sacred kingfisher* 1 5 1 3 100 whiskered tern 1 25 white-faced heron 2 1 1 75 white-necked heron 1 25 Rails and shoreline gallinules black-tailed native-hen 55 25 Raptor black kite 1 2 50 nankeen kestrel 3 25 whistling kite 2 2 1 75 Large wading birds Australian white ibis 1 25 brolga 2 25 yellow-billed spoonbill 5 25 J= listed under JAMBA; C= listed under CAMBA; R= listed under ROKAMBA; V=Vulnerable (NSW TSC Act); E= Endangered (NSW TSC Act); *= breeding activity observed Figure : Species richness recorded across sites in 2015-16 monitoring period. Figure : Number of waterbirds/ha recorded across sites in 2015-16 monitoring period. To further describe patterns in bird community composition, multivariate analysis was undertaken on species abundance data. From the nMDS plots, there appeared to be separation of the data when grouped by season and zone (Figure N8). However, PERMANOVA analysis suggested these differences were non-significant. While the differences between groups were non-significant, SIMPER analysis suggested that different species were associated with each grouping (Table N4).
Australian wood duck, sacred kingfisher (Todiramphus sanctus) and black-fronted dotterel contributed to the variation within the October 2015 sampling sites, while the grey teal, Pacific black duck (Anas superciliosa), Australian pelican (Pelecanus conspicillatus), white-faced heron (Egretta novaehollandiae) and whistling kite (Haliastur sphenurus) contributed to the grouping of the March 2016 sampling sites. In the Warrego channel, the grey teal, whistling kite, Australian wood duck, Australian pelican and Pacific black duck contributed to the variation, while the black-fronted dotterel and sacred kingfisher were the only species recorded in the Western Floodplain site. Figure : nMDS plot of waterbird abundance data grouped by sampling time and zone. Table : SIMPER results of species contributions to groupings in community composition data. Contributions of species for the floodplain sites could not be calculated due to only one site containing data. All species present at this site are listed. Grouping Species Contribution to grouping (%) October 2015 black-fronted dotterel 35.35 sacred kingfisher 30.06 Australian wood duck 14.6 March 2016 grey teal 26.58 Pacific black duck 16.67 Australian pelican 16.11 white-faced heron 12.9 whistling kite 12.23 River grey teal 19.14 black-fronted dotterel 15.66 Australian wood duck 15.53 Australian pelican 13.57 Pacific black duck 12.25 Floodplain black-fronted dotterel - sacred kingfisher - Waterbird breeding and functional guilds Waterbird breeding was only observed in two species in the 2015-16 monitoring period; the black-fronted dotterel (Australian-breeding charadriiform shorebird) at Boera Dam in October 2015 and sacred kingfisher (piscivore) at Booka Dam in March 2016. Nine of the ten functional guilds were represented in the Selected Area in the 2015-16 monitoring period with reed-inhabiting passerines absent in both monitoring periods. Eight guilds were represented in October 2015 and seven guilds were represented in March 2016 (Figure N9). Dabbling and filter-feeding ducks, which includes grey teal, the most abundant waterbird species observed in the 2015-16 monitoring