Eastern Australian waterbird numbers fall 50% amid dry conditions

Waterbird numbers in eastern Australia have fallen by half in one year amid dry conditions.

The latest annual survey of waterbirds in eastern Australia, led by the University of New South Wales (UNSW) Sydney, spotted 287,231 birds between August and October, down 50.4 percent from 579,641 birds in 2023.

The survey, conducted every year by researchers and government collaborators since 1983, covers one-third of the Australian mainland and is one of the most important datasets on the health of biodiversity in river and wetland areas.

The survey team attributed the sharp decline in numbers to drier conditions resulting in a drop in waterbird breeding in 2024 following wet years with widespread flooding in 2021 and 2022.

"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," Richard Kingsford, leader of the survey from UNSW, said on Tuesday.

"We had a good bounce in numbers after good breeding in the flood years of 2021 and 2022, but numbers have now dipped below the long-term average again, with little breeding in 2023 and 2024," he said.

The 2024 survey found that overall numbers, the number of species breeding and the total size of wetland area, three key indicators of waterbird health, have continued to show significant long-term declines.

The total area of wetlands was 122,283 hectares, which the report said was well below the long-term average.

The highest abundance of waterbirds was found in the northwestern regions of the state of Queensland, which covers the continent's northeast, where 17 percent of all surveyed birds were observed.

(Cover: A pied stilt forages in the shallow water, Australia. /CFP)