Crested pigeons communicate without even opening their beaks. The birds have a built-in alarm system that’s set off by fluttering feathers when flying away from danger, researchers report November 9 in Current Biology.
In animals, nonvocal sounds are not uncommon. “All animals produce sound as we move, even humans, and that sound can be useful to those that hear it,” says study coauthor Trevor Murray, a biologist at the Australian National University in Canberra.
Among birds, the go-to instruments for creating these sounds are the wings. Some birds, like Ecuador’s club-winged manakins, use wing sounds in mating rituals, while other species such as mourning doves make nonvocal sounds in times of perceived peril (SN: 7/30/05, p. 67). But whether such noises truly represent communication in the same manner that bird songs and calls do is hard to prove.
Crested pigeons (Ochyphaps lophotes) have 10 primary flight feathers on each wing. The eighth — that is, the third from the top of a bird’s extended wing — doesn’t look like a normal feather; it’s slender and oddly shaped. A 2009 study suggested that this specialized wing feather might be behind the noisy takeoffs that occur when crested pigeons sense danger.