Threatened species & ecological communities

Nationally Threatened Birds of the Murray Darling Basin

Environment Australia

The Murray Darling Basin bird fauna is distinguished by an inordinately high number of near threatened species and subspecies, mostly woodland species. The Australian Action Plan for Birds 2000 identifies 24 birds on the brink of being considered nationally threatened, and 14 that are already threatened.

Most temperate woodland habitat has been cleared, including 85 per cent of box-ironbark forests in Victoria and over 70 per cent in New South Wales. Almost all the better quality agricultural land has been cleared, which is of particular consequence for migratory species such as the Regent Honeyeater and Swift Parrot.

Remaining woodland habitat is fragmented and inferior habitat on poorer soils. It continues to be degraded by removal of living and dead timber, which provides essential habitat requirements for most bird species, and there is an ongoing decline in tree health, as seen in areas of trees suffering dieback.

Factors such as salinisation, over-grazing and weed invasion gradually make the remaining fragments unsuitable for birds. Within fragments, essential habitat features that may be lost are leaf litter and sticks and their associated invertebrates, hollows suitable for nesting by cockatoos, parrots, owls and treecreepers and key food plants. Introduced predators such as foxes and cats may have exacerbated habitat loss and caused further declines in ground dwelling birds such as Australian Bustards and Turquoise Parrots.

Embedded in the woodlands are wetlands, the health of which is linked to woodland management. These wetlands, many of which have been drained or degraded by overgrazing, are key habitats for species such as bitterns and Painted Snipe. Native grasslands, essential habitat for Plains Wanderers, are also threatened by pasture improvement for agriculture, fragmentation and degradation.

Mallee areas within the basin support a high number of threatened birds, such as the Black-eared Miner, Malleefowl, Regent Parrot and Mallee Emu-wren. The principal threat to mallee birds is extensive wildfire. Many species are sensitive to fire, preferring mallee that has been unburnt for several years, and large-scale fires have the potential to eliminate such species even from large mallee areas. Past clearance of mallee has caused substantial habitat loss and continuing problems associated with fragmentation.

Loss of mature and dead trees along the Murray and Wimmera Rivers, as a result of logging for timber and firewood collection, ringbarking on agricultural land, salinisation and water-logging, has reduced the area of breeding habitat available to Major Mitchell's Cockatoo and Regent Parrots.

Core species and subspecies and their recommended conservation status

Locally Extinct

Endangered

Vulnerable

Near Threatened

For general information about threatened species, or to ask about obtaining a hard copy of the Bird Action Plan contact the Department of the Environment and Heritage's Community Information Unit on 1800 803 772 or email ciu@environment.gov.au