Wednesday, 22 November 2023
Although the Australasian Bittern is quite a large bird, it is also a difficult bird to find. A combination of the impenetrable reedbeds they inhabit, their shy nature, cryptic plumage and their elusive behaviour all make it one of Australia’s most elusive wetland birds. It’s no surprise, then, that little is known about them — even which wetlands they inhabit.
We know that they occur from Western Australia across to New South Wales and south to Tasmania, but at which wetlands? BirdLife Australia’s Australasian Bittern Listening Surveys project is making tremendous inroads into clarifying exactly where Australasian Bitterns are.
The Australasian Bittern Listening Surveys take advantage of the bitterns’ habit of calling during the spring and summer months, mainly during the twilight hours in early morning and in the evenings. These booming calls are surprisingly loud, carrying across some distance in the still air. Stationing volunteers at potential bittern wetlands to listen out for their distinctive calls is a great way of discovering if there are bitterns skulking about among the reeds.
Surveys at wetlands scattered across the entire range of the Australasian Bittern in late October have recorded the species calling during about a quarter of the 81 surveys conducted so far. Bitterns were recorded at two wetlands in Western Australia, where the species is especially rare (including one at the aptly-named Big Boom Swamp), while in the eastern states, most records (nine) were from Victorian wetlands; two were seen in wetlands in NSW and one at Bool/Hacks Lagoons in South Australia. Of course, not hearing a booming bittern doesn’t mean that there are no bitterns there, but conversely, hearing a bittern obviously confirms its presence at the wetland.
The Australasian Bittern Listening Surveys run until the end of December. If you would like to take part in upcoming bittern listening surveys, click here for more information.
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