Return of the waterbirds

Return of the waterbirds

Inland wetlands gradually vacated as La Niña wanes

After three years dominated by La Niña conditions, characterised by higher-than-usual rainfall in many parts of the continent, much of Australia has been transformed.

Across inland Australia, the regular drenching rains in many regions have caused entire networks of waterways to become turgid, inundating floodplains and filling wetlands as they flow across the saturated landscape. The result has been the greening of Australia’s usually arid interior, and the flooded wetlands have supported unbridled breeding by myriad waterbirds, many of which have flown long distances as they moved from coastal regions to the inland.

We still don’t understand how the waterbirds know that the conditions hundreds or thousands of kilometres away are favourable for breeding, but however they find out, whenever it’s wet in Australia’s interior, they head inland in their droves.

“How the birds know it’s raining inland is one of the great mysteries of Australian ecology,” said Mick Roderick, from BirdLife Australia. “When it rains in inland Australia, a lot of birds will fly there and that’s where they’ll breed.”

Across the Murray–Darling and Lake Eyre Drainage Basins, often-dry wetlands have been teeming with nesting waterbirds — pelicans, ibis and spoonbills, egrets, herons and night-herons, coots and cormorants, swans, and ducks galore!

However, with the rains gradually easing off recently (at least in most areas), the water levels in many of the wetlands have begun to recede a little, triggering an exodus back towards the coasts, and many birdwatchers are enjoying witnessing its early stages, with new arrivals appearing each week.

Increasingly, waterbirds which have bred at inland wetlands — White-necked Herons, Freckled Ducks, Australasian Shovelers, Pink-eared Ducks, Whiskered Terns, Eurasian Coots to name just a few — have started to turn up at wetlands far removed from the flooded interior.

“We’re starting to see a lot of waterbirds that have been absent [from coastal wetlands] for the past couple of years starting to return to our local wetlands,” Mick said.

As the wetlands dry out further, the number and diversity of birds returning to coastal areas is certain to increase in the coming weeks and months.

Enjoy the spectacle — and keep an eye out for any Australian Painted Snipe.