One of Australia’s largest wildlife surveys has found that Drier conditions have led to waterbird numbers in eastern Australia plummeting by 50% compared with 2023.
Conducted annually since 1983, the eastern Australian waterbird aerial survey is one of the world’s longest continuous bird counts as well as one of the largest by geographical distance covered. The survey spotted 287,231 birds this year – half the 579,641 birds recorded in 2023. The number of birds in the 2024 report was the 22nd highest in 42 years of the survey, well below the long-term average.
The director of the centre for ecosystem science at the University of New South Wales, Prof Richard Kingsford, who leads the aerial surveys, said there was a “wistful optimism” that after wet years associated with the triple La Niña there would be a sustained boost in bird numbers.
“In 2021 and 2022 there was a lot of flooding everywhere, and we know that there were a lot of birds breeding, but we just haven’t seen the same sort of recovery,” he said.
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The survey, which tracks more than 70 species of waterbirds, covers a third of the Australian continent – an area measuring 2.7m square km, or 11 times the size of the UK. It comprehensively tracks the distribution and breeding of waterbirds as well as changes in the major rivers and wetlands of the Murray-Darling basin.
Three of four major markers of waterbird health – overall numbers, numbers of species breeding and wetland area – were down, continuing a trend of significant long-term declines.
The abundance of breeding birds fell to well below the long-term average and was one of the lowest on record.
“The areas that these birds breed in and rely on are floodplain areas,” Kingsford said. “So much of what we’ve done in building dams and diverting water has [affected] that flood water that’s so critical for the wetlands.
“We’re also increasingly worried about the effects of climate change in terms of the drying out of the south-east of the continent.”
Story was adapted from the Guardian.