Document ID: chunk:federal_register_of_legislation:F2023L00138:front:0:p9
Version: federal_register_of_legislation:F2023L00138
Segment Type: other
Provision Reference: 
Character Range: 22683–25731

species is estimated to be 5.5 years (BirdLife International 2019).

1.7            Habitat critical to the survival of the Australasian Bittern

             As noted above, the habitat, or biophysical environment, of the Australasian Bittern varies across its range, so it is not possible to generate one detailed description or definition of habitat critical to survival. The habitat critical to the survival of the Australasian Bittern may be more usefully defined at a bioregional scale that considers the combination of plants, animals, water depth, geology, landforms, and climate that is relevant to a geographical unit.

             In general, Australasian Bitterns occur mainly in freshwater wetlands in the temperate southeast and southwest of Australia and, exceptionally, in estuaries or tidal wetlands (Marchant and Higgins 1990; Figure 1). Australasian Bitterns' preferred habitat comprises wetlands with dense vegetation, especially where there is a mosaic of cover, from 0.5–3.5 metres in height, where they forage in still, shallow water up to 0.3 m deep, often at the edges of pools or waterways, or from platforms or mats of vegetation over deep water. They favour freshwater habitats with permanent or seasonal water, particularly those dominated by sedges, rushes and/or reeds (e.g. Phragmites, Cyperus, Eleocharis, Juncus, Typha, Baumea, Bolboschoenus) or cutting grass (Gahnia) growing over a muddy or peaty substrate (Marchant and Higgins 1990). In south-western Australia the species also occurs in wetlands where thickets of wetland shrubs (e.g. Melaleuca, Agonis spp.) provide patches of tall cover within sedge-dominated habitat. In the Murray–Darling Basin, Australasian Bitterns occur in floodplain swamps that may include lignum (Duma florulenta) shrubs within sedge or reed beds as well as in commercial rice-fields (NSW Riverina). Despite occurring in a range of wetland types, breeding is only known to occur at a smaller number of locations.

   As a guide, habitat critical to the survival of the Australasian Bittern can be considered to include:
     •       Any natural wetland habitat where the species is known or likely to occur (breeding or foraging habitat) within the indicative distribution map (Figure 1).

   Habitat critical to the survival of the Australasian Bittern occurs across a wide range of land tenures, including on Indigenous Protected Areas, freehold land, conservation reserves, and national parks. It is essential that the locations where the species regularly occurs is given the highest protection and conservation measures target these productive habitats. Areas that buffer nesting and foraging habitats should also be considered in management for the species. Buffer zones will depend on the nature and location of the activity (e.g. adjacent to the wetland vs activity in the catchment) and can be informed by expert opinion.

   When considering developments in any part of the Australasian Bittern's range, including in areas where the species 'may occur', surveys for