Friday, 20 December 2024
Latest Eastern Australian Waterbird Survey reveals dramatic decline in waterbirds counted in the Murray‒Darling Basin.
Now in its 42nd year, the Eastern Australian Waterbird Survey is one of the world’s longest and largest continuous bird counts.
Every October, UNSW’s annual waterbird survey sees researchers and government collaborators count waterbirds from the air – covering up to 2,000 wetlands in the Murray‒Darling Basin over the eastern third of Australia.
Data collected from these aerial surveys helps track long-term changes in waterbird abundance, diversity, distribution and breeding, while helping measure the health and changing conditions of wetlands and rivers. In turn, this data informs State and Federal management of wetlands and migratory waterbird conservation efforts.
Map showing 2024 Eastern Australian waterbird survey flight path via UNSW Sydney
But in 2024, the aerial survey team counted just 287,231 waterbirds – around half of the 2023 tally of 579,641 birds.
While it’s normal for waterbird numbers to fluctuate in response to the boom–bust cycles of Australia’s inland wetlands, the latest Eastern Australian Waterbird Survey results are well below the long-term average – pointing to higher temperatures and drier conditions across eastern Australia in 2024.
Three of the four major markers of waterbird health (overall numbers, numbers of species breeding and total wetland area) were also down, with the abundance of breeding birds among the lowest on record.
While this continues a concerning trend of significant long-term declines, the sudden and dramatic decline in waterbird numbers in the region is alarming.
“We know that when it starts to dry up, the floodplains dry up and waterbirds do not have the food to breed in large numbers, so they concentrate on remaining lakes and swamps, which is what we saw this year,” says UNSW’s Professor Richard Kingsford, who leads the aerial surveys.
While the record-breaking La Niña event of 2020–2022 saw widespread flooding, drier conditions over much of south-western and south-eastern Australia in 2024 left waterbirds in the Murray‒Darling Basin with little habitat to breed.
However, other parts of the country – including the Channel Country, southern Queensland, the Kimberley and Barkly region in the NT – saw above average rainfall in 2024.
The Eastern Australian Waterbird Survey doesn’t cover the whole range of many waterbird species. Since waterbirds are highly mobile, it’s possible that many have moved north and west to take advantage of more favourable conditions outside the survey’s view.
Chris Purnell, BirdLife Australia’s Manager of Wetland and Migratory Shorebirds, acknowledges this challenge.
“Gaps in monitoring of significant wetland systems in northern Australia impact our ability to effectively track national waterbird trends and understand how populations are structured,” he says. “We need to improve our knowledge of how waterbirds are using other basins.”
“However, the Murray‒Darling Basin is a heavily regulated system, and the latest Eastern Australian Waterbird Survey results show that more needs to be done in dry years to effectively invest in and deliver environmental water to improve resilience in waterbird populations.”
Protecting Australia’s wetlands
Australia’s wetlands and waterways support a huge diversity of birdlife, but despite their significance, these fragile ecosystems are the most threatened habitat on the planet. The growing effects of climate change, including increasing temperatures, changing rainfall patterns and more frequent and intense droughts, are accelerating the drying out of our wetlands.
As the world’s wetlands continue to disappear at an alarming rate, the latest Eastern Australian Waterbird Survey results are a stark reminder of their importance – and why our wetlands need our care and protection more than ever.
We need State and Federal governments to step up to improve the overall health of Australia’s wetlands – and ensure that our wetland-loving wildlife aren’t lost in the scramble for water resources.
“It’s really contingent on governments to get their act together to work better to protect the wetlands of the Murray‒Darling that still survive,” says BirdLife Australia’s National Public Affairs Advisor Sean Dooley.
“And to make sure that they replenish them and nourish them, or else this fearful decline of our waterbird population will continue.”
Meanwhile, BirdLife Australia’s Coastal and Wetlands Birds team is helping monitor, restore and protect these critical habitats and the birds which rely on them – working with land managers, farmers, volunteers, governments, Traditional Owners, researchers and conservation and community groups across Australia to conserve wetlands and wetland birds.
The Eastern Australian Waterbird Survey is led by UNSW’s Centre for Ecosystem Science with major NSW government partner the Department of Climate Change, Energy, the Environment and Water (DCCEEW) and other Australian state government agencies.
Celebrating World Wetlands Day! Discover why we need wetlands – and why they need us.
This program focuses on the conservation of wetland and waterways and the birds they support.
Subscribe for the latest conservation news, upcoming events, opportunities, and special offers.
