Document ID: chunk:federal_register_of_legislation:F2007L01320:body:0:p3
Version: federal_register_of_legislation:F2007L01320
Segment Type: other
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Character Range: 5786–8672

males increased by 6% (R Hill in litt.). This may be a seriously negative population trend as it indicates that in just six years, production of young has fallen such that the time required to replace the adult population has more than doubled from 16 to 37 years.

1.4 Habitat critical for survival
The habitat critical to survival of the South-eastern Red-tailed Black-Cockatoo is defined as all potential habitat within its 'current normal range' (Figure 1). Potential habitat includes feeding, nesting and roosting habitat as described in Section 1.5. Potential habitat has been mapped to the extent possible (Figure 1) as areas where habitats are known to occur, areas where habitats are likely to occur and areas where habitat may occur (but the location is unknown).

The South-eastern Red-tailed Black-Cockatoo is restricted to Desert Stringybark Eucalyptus arenacea and Brown Stringybark E. baxteri woodlands occurring on deep aeolian sands in the Glenelg, Wimmera and Naracoorte Plains, and adjacent woodlands of River Red Gum Eucalyptus camaldulensis, Yellow Gum E. leucoxylon and Buloke Allocasuarina luehmannii. Much of the stringybark feeding habitat in Victoria is on public land, whereas much of the Buloke feeding habitat and breeding habitat throughout its range, and stringybark feeding habitat in South Australia, is on private land (Hill and Burnard 2001, Koch 2003). None of the habitat critical to survival identified is within Commonwealth areas.

1.5 Habitat requirements
Feeding habitat - The cockatoo is highly specialised, feeding primarily on the seeds of Desert and Brown Stringybark (Eucalyptus baxteri and E. arenacea) , and seasonally on the seeds of Buloke(Allocasuarina leuhmannii). Feeding habitat is much more fragmented in South Australia (87% cleared) than in Victoria (42% cleared). In South Australia the two stringybarks occur in plant communities 11, 12, 80, and 97 (Croft et al. 1999). In Victoria, most records of the birds are from three Ecological Vegetation Classes (EVC): Heathy Woodland, Herb-rich Heathy Woodland and Damp Sands Herb-rich Woodland. However, there are several other EVCs within the  range where one of the two stringybark species can be a dominant or co-dominant tree (DPMC 1999).

The birds feed in blocks of forest and scattered paddock trees. Desert Stringybark fruits on a three year cycle and Brown Stringybark on a 2-4 year cycle (Koch 2003), with the cockatoos feeding almost entirely on the species that has fruited most recently (Attiwill 1960, Joseph 1982). Desert Stringybark makes up only 28% of the stringybark habitat in the range, and this species is likely 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