Clifford B Frith | Guest Contributor
My good friend and keen wildlife photographer, Andy Mason, drove to Rinyirru (previously Lakefield) National Park on Cape York Peninsula to photograph whatever wildlife presented itself to him. Commencing at 07:14 on 31 August 2023 he photographed Wandering Whistling-Ducks at various points on a waterhole within Rinyirru National Park.
Upon his return home he was showing me the photographic results of his trip on my computer. As a picture of Wandering Whistling-Ducks appeared and disappeared, I quickly asked him to return to it – because its content instantly struck me as most unusual. And indeed, it proved to be so, in a most dramatic way!
What Andy had photographed was five Wandering Whistling-Ducks forming a perfect circle, each stationary bird facing outward. In that remarkably symmetrical formation, they were all clearly vigorously kicking downward through the water to create an upwelling, or vortex, of water within their circle to raise vegetable matter, and doubtless also some animal life, from the substrate some half to a metre below the surface (see photograph). One duck at a time would then dive into the middle of the circle to forage, apparently upon vegetable matter but possibly also/or animal life.
Andy had serendipitously captured an image of Wandering Whistling-Ducks doing something that that species, the other six kinds of whistling-ducks found around the world, and none of the other 165 species of waterfowl, had ever been recorded doing — communally cooperating to forage from the surface of water in a circular formation while, somewhat surprisingly, facing outward.
A truly remarkable, novel discovery of sophisticated and systematic cooperative foraging, particularly given the very long-term intensive studies of waterfowl world-wide, and the extensive knowledge of them gained by biologists and ornithologists to date! A most uplifting experience for all concerned.
Editor’s note: This article is an abstract from Frith CB & Mason A (2024). Communal cooperative aquatic foraging by Wandering Whistling-Ducks Dendrocygna arcuata. Australian Field Ornithology 41, 4–5. http://dx.doi.org/10.20938/afo41004005