Wetlands Australia 32: Prioritising important floodplain habitat for bush birds

Author: Rowan Mott, University of Melbourne

If you think about floodplains and the birds they support, it’s probably ducks and swans, herons, and cormorants that spring to mind. But floodplains are also a critical part of the habitat network for a wide range of birds that are not usually thought of as wetland-dependent.

Bush birds including scarlet robins and brown treecreepers benefit from the high productivity and connected nature of floodplain vegetation. Floodplains also shield bush birds to some extent from the effects of drought and temperature extremes because of their shallower water table and the presence of water in the main stream channel. These factors mean that floodplains will play an important role in safeguarding many bush birds into the future.

Scarlet robin

The Murray-Darling Basin has more than 58,000 km² of floodplains. Their enormous extent, and the requirement to balance social, economic and environment requirements under the Basin Plan, mean that it is important to identify and prioritise those floodplains that are most important for biodiversity.

We are modelling how habitat suitability for more than 100 species of bush birds has fluctuated since 1998. These species were specially selected because they are commonly associated with Murray-Darling Basin floodplains. Our habitat suitability predictions can then be used to identify which floodplains consistently provide good quality habitat for these birds. This enables us to rank how each floodplain stacks up against the others, highlighting which should be prioritised for management to ensure they retain their habitat value.

Despite different species having spatially different habitat suitability predictions, the habitat suitability prediction for each species changed only slightly from year-to-year. This was particularly so for areas with relatively high habitat suitability, whereas areas with relatively low habitat suitability tended to vary more across years. This suggests that floodplains identified as priorities for management are likely to remain priorities for management for the foreseeable future.

Preliminary spatial prioritisation analyses based on only threatened species suggest that priority floodplains occur in distinct regions of the Murray-Darling Basin, with floodplains near Morgan in South Australia, and Lightning Ridge and Griffith in New South Wales all having a prominent role in the conservation of threatened bush birds. An exciting next step will be seeing how the addition of non-threatened bush birds influences the outcomes of spatial prioritisation.

Further information

• Threatened Species Recovery Hub, National Environmental Science Program: Threatened bird conservation in Murray-Darling Basin wetland and floodplain habitat