Document ID: chunk:federal_register_of_legislation:F2007L01320:body:0:p4
Version: federal_register_of_legislation:F2007L01320
Segment Type: other
Provision Reference: 
Character Range: 8428–11231

to be a more limiting resource than Brown Stringybark (Koch 2003).

The only other food source regularly used is the seeds of Buloke, which is part of the nationally threatened ecological community - 'Buloke Woodlands of the Riverina and Murray Darling Depression Bioregions. These woodlands have been extensively cleared in the past, and the remnants that survive face ongoing major threats from incremental clearance, grazing by rabbits and stock, invasion by exotic plants, weedicide application and fertiliser drift. The community is poorly represented in conservation reserves throughout its range.  Nearly all remaining Buloke occurs on private land used for agriculture, and no significant area is reserved. Most remnant Buloke occurs as scattered trees in grazed or cultivated paddocks (practices that prevent regeneration), or as thick regrowth of trees on roadsides which are too young and too dense to produce large amounts of seed, and to be suitable for foraging by Red-tailed Black-Cockatoos (Maron 2004). Buloke seed is only available during January to March, and Bulokes do not produce a substantial crop every year (Maron and Lill 2004). While cockatoos have only been observed to forage in trees larger than 19cm dbh (diameter at breast height), and hence possibly over 100 years old (L. Morcombe, University of Ballarat, unpublished data), they prefer trees over 200 years old (Maron and Lill 2004).

Nesting habitat - The cockatoo requires very old, large, hollow eucalypts for nesting (Joseph et al. 1991). Over 95% of known nest sites are within 2km, and all within 5km, of >5 ha blocks of stringybark (Hill and Burnard 2001). They show a preference for dead trees (81%), but also use live trees. Nests are most often found in farmland with scattered live and dead Red Gums (Joseph et al. 1991). In South Australia, the remaining Red Gum communities in the lower South-East are 'vulnerable' with 9.7% of the estimated original area remaining and 0.3% in reserves (Croft et al. 1999). In south-west Victoria, Plains Grassy Woodland is 'endangered' with an estimated 4% remaining, of which 1.5% is reserved (DPMC 1999). Nests have been recorded in Eucalyptus camaldulensis, E. baxteri, E. arenacea, E. viminalis, E. leucoxylon and E. fasciculosa.

Roosting habitat - The cockatoo usually roosts in clumps of tall eucalypts, and sometimes use the same site each night for many months (R Hill in litt.). Of 19 roost sites, 79% were in copses of Red Gums, 16% in Yellow Gums and 5% in Manna Gums. Thirteen of these sites (68%) were on private land.

2. Threats

Threats have been identified through a number of studies on the South-eastern Red-tailed Black Cockatoo, undertaken since 1997.  Threat priority has been determined by the recovery team members with expert advice and with