DARLING RIVERINE PLAINS BIOREGION Background Report

16/08/02 Darling Riverine Plains Bioregion Background Report
Threats to reptile populations mostly come from habitat modification resulting from clearing,
grazing pressure, cropping, predation, urban development, pasture improvement and changed
fire regimes (Cogger et al. 1993).
5.3.3 Regionally endemic species and significant populations
Ten reptile species recorded in the DRP are either endemic to or have a majority of their
distribution within the Darling Basin (Ayres et al. in press). These are: Emydura macquarii,
Delma plebeia (leaden delma), Anomalopus leuckartii (two-clawed worm-skink),
Anomalopus mackayi, Ctenotus allotropis, Ctenotus brachyonyx, Egernia modesta,
Hemiaspis damelii (grey snake), Pseudechis guttatus and Simoselaps australis (coral snake).
All except Ctenotus brachyonyx (only potential occurrence) have been recorded in the
bioregion.
No threatened populations of reptiles have been identified in the bioregion under the TSC Act
but changes in the distribution of several reptile species in the DRP have been noted. Morelia
spilota has been recorded from the vicinity of the Darling and Macquarie Rivers, however
populations around Bourke may have become locally extinct as the last record for this species
in this area was prior to 1909 (Shine 1994; Sadlier & Pressey 1994). The range of
Anomalopus mackayi appears to have contracted eastwards, with no recent records from west
of Moree (Cogger et al.1993). There has been no detailed assessment of the status of
populations of reptiles in the DRP.
5.4 BIRDS
5.4.1 Known species diversity and distribution
There are 2 412 100 records of 319 bird species in the DRP databases. Parrots, cockatoos,
honeyeaters, wrens, crows and birds of prey are the most frequently recorded. The
distribution of records since 1970 across the DRP is uneven and there are many mapsheets
with few bird records when compared with coastal NSW (Map 34, Map 35) (NPWS 1999c).
The number of bird records per mapsheet also declines from south to north across the state.
The central Macquarie River, Menindee Lakes and the Culgoa River floodplain have the
highest number of bird records.
Eighty-two species were recorded in the northern floodplain biodiversity survey, with an
additional 73 species having been previously known from this area (Smith et al 1998). In the
Narran Lakes area, 105 species of land birds have been recorded including 85 species listed
by Smith (1993). In the Gwydir watercourse, Spark (1998) recorded 75 bird species,
including two threatened birds, the barking owl and black-chinned honeyeater. Many
additional species, including several threatened species, are recorded on the NSW NPWS
Atlas for the area (Spark 1998). Dick and Andrew (1993) recorded 112 species of native bird
and one introduced species in their systematic surveys of fauna in the Culgoa and Birrie River
floodplains. Like the Narran lakes, most bird species were from the woodland habitats.
Waterbirds are a significant component of the bird fauna of the DRP and the wetland bird
communities, particularly in the Macquarie Marshes and Narran Lakes, have been more
intensively studied than terrestrial communities. Both these wetlands are significant sites for
waterbird breeding in southern Australia and during the floods of 1990 supported the largest
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