Science for Saving Species Research Findings Factsheet Project 4.4.7
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Science for Saving Species Research findings factsheet Project 4.4.7 Woodland bird conservation in Murray-Darling Basin floodplain habitat In brief Background Floodplain ecosystems in south- The Murray-Darling Basin (MDB) that was collected over a 21-year eastern Australia’s Murray-Darling provides vital habitat for many period (1998–2018). Basin (MDB) are under stress species, including terrestrial bird The priority locations we identified from changes to the hydrologic species that depend on floodplain differed depending on management regimes, grazing and vegetation forests and woodlands. The objectives. When the focus was to clearing. Many species, including ecological condition of floodplain identify core habitat for threatened waterbirds and terrestrial birds, rely vegetation is in decline due to an bird species, floodplains along the on floodplain habitats for parts of array of threats, including changed western reaches of the Murray River their life cycles, with floodplain hydrologic regimes, and pressures had the highest priority. Conversely, ecosystems representing some of from invasive species. We aimed when non-threatened floodplain– the largest continuous stretches to provide decision support for dependent species were examined, of habitat for terrestrial woodland MDB managers by identifying the highest priority sites were birds. Threatened terrestrial bird priority habitat areas for floodplain- concentrated in the north of the species that are associated with associated terrestrial bird species. MDB to the east of Cunnamulla MDB floodplain habitats include and east of Lightning Ridge. the painted honeyeater (Grantiella We used the spatial prioritisation picta), regent parrot (Polytelis tool Zonation to create maps of Our findings can be used to anthopeplus monarchoides), floodplain vegetation habitat zones. efficiently allocate management and the superb parrot (Polytelis The maps showed the locations resources, such as environmental swainsonii). The management of of terrestrial floodplain bird habit water, so that conservation these ecosystems has important based on a prioritisation ranking. outcomes for these bird ramifications for the conservation The predictions were based on data species are optimised. of these species. State and federal governments have used management actions aimed at improving the health of the MBD system. For example, 16 wetlands have been listed as Wetlands of International Importance under the Ramsar Convention. In addition, statutory environmental water holders have been established to manage portfolios of water holdings for achieving environmental outcomes in floodplain, wetland and riverine environments, and Superb parrot. Image: Patrick_K59, CC BY 2.0 Wikimedia Commons Background (continued) What we did numerous other environmental We compiled a database of occurrence and a set of restoration activities are taking 4,555,939 presence records from environmental variables that place throughout the MDB. These existing data sources for 108 bird indicated terrestrial bird occurrence. factors represent opportunities species that had previously been The environmental variables for improving outcomes for identified as occurring commonly included measures of habitat native species who use the in MDB floodplain vegetation. extent, habitat condition and floodplain habitats at various We focused on data collected variables that affect bird distribution points in their life cycle. over a 21-year period between 1998 through their effects on physiology (e.g., longest run of consecutive Terrestrial birds are not commonly and 2018. These data were used hot and dry days). Some variables considered in the management to build individual habitat suitability were constant across years (e.g., of floodplain ecosystems, and models for each bird species. as such, further research and Two separate models were elevation), whereas other variables targeted management strategies produced for each species, one were dynamic across years are required for this community. for the breeding season and one (e.g., cumulative rainfall). Climate change–induced for the non-breeding season. We examined three different increases in the frequency and We created maps to visually display scenarios for prioritising habitat severity of drought in the MDB habitat suitability for each bird zones for terrestrial birds. First, will increase the importance species in each of the 21 years we identified priority areas that of the region’s floodplains for from 1998 to 2018. maximised the core habitat for the bird communities they We used a spatial prioritisation three threatened terrestrial birds, support. Conservation planning approach called Zonation to the painted honeyeater (Grantiella can help identify habitats and identify the most important habitat picta), regent parrot (Polytelis locations which support key areas within MDB floodplains. anthopeplus monarchoides), biodiversity. Knowing where and the superb parrot (Polytelis The modelling identified floodplain to target management actions swainsonii). Second, we identified areas that consistently provided and resources could assist priority areas that would maximise habitat with high suitability conservation of floodplain- the habitat for 50 floodplain– during the 21-year study period. dependent terrestrial birds dependent terrestrial bird species. This timespan included periods and their habitats. Finally, we identified priority areas of extreme drought (e.g., the that would maximise the habitat Millennium Drought) as well as for all floodplain–associated years with above average rainfall. Main aims terrestrial bird species. Maps We developed habitat suitability were produced to identify areas This project aimed to identify models by modelling the of conservation prioritisation which locations within the relationship between species for each of these three scenarios. Murray-Darling Basin are the most important habitat for threatened bird species, floodplain–dependent species and floodplain–associated bird species. Overall, we wanted to identify where protection and conservation efforts could be best concentrated within the MBD for the benefit of both threatened and floodplain– dependent native birds. Floodplain-dependent yellow rosella. Image: Rowan Mott Key findings We produced predicted habitat National Park, Barmah National Park, suitability maps with good predictive and Hattah-Kulkyne National Park, performance for 72 of the 108 bird as well as the New South Wales species associated with floodplain Central Murray State Forests Ramsar vegetation. Bird species we could site, Barmah Forest Ramsar Site not produce satisfactory models and Riverland Ramsar Site. for had a widespread occurrence, Some Ramsar wetlands, such as the and therefore did not have a strong Barmah Forest and Hattah Lakes affinity with any habitat type. Ramsar Sites, were almost entirely For most of the bird species ranked within the top 10% examined, the seasonal habitat of priorities when focusing on suitability predictions varied little habitat for threatened species. between years throughout the The regent parrot had a very 21-year study period. This was the restricted range, with a strong case during both the breeding preference for floodplains, and and non-breeding seasons for was the main driver of these the regent parrot, superb parrot patterns. On the other hand, and painted honeyeater. the superb parrot and painted However, for a few bird species honeyeater have a wider distribution, Painted honeyeater. Image: Stuart Harris CC BY-SA 2.0 Wikimedia Commons variations were noticeable in the and have areas with high habitat predicted habitat suitability from one suitability in both floodplain and year to the next. This was the case non–floodplain areas. Only very small areas of individual Ramsar sites were represented in the for the little friarbird and the barking Scenario 2. Floodplain–dependent top 10% of priorities for floodplain- owl during non-breeding seasons. terrestrial bird species dependent species and floodplain- We produced a set of maps that Floodplains along the Barwon, associated species. Floodplains in clearly identify the priority areas Boomi and Macintyre Rivers east the very south of the MDB, such that would maximise bird habitat of Lightning Ridge were ranked as those along the Murray River under each of the following as high priorities for floodplain– from Swan Hill eastward were three scenarios. dependent birds. Similarly, consistently ranked as lower Scenario 1. Threatened terrestrial floodplains extending west from the priorities for these bird groups. bird species Nebine Creek east of Cunnamulla, and floodplains along scattered For all three scenarios, floodplains Floodplains along the Murray creeks west of Menindee also along the Darling River between River from Swan Hill westward ranked highly in this scenario. Bourke and Menindee were never were identified as the highest ranked as high priority habitat for Scenario 3. Floodplain–associated priority habitat for the threatened terrestrial birds. Floodplains along terrestrial bird species painted honeyeater, regent parrot the Darling River and floodplains and superb parrot. (See Figure 1.) Floodplains east of Cunnamulla in the very south of the MDB were Under this scenario the model also along the Mungallala, Paterson also ranked low for floodplain- identified high priority floodplains and Widgeegoara Creeks, and associated terrestrial birds. Lower- along the eastern reaches of the floodplains in the headwaters of ranked areas