Crested pigeons use feathers to sound the alarm

November 09, 2017

Many animals will sound an alarm to alert other members of their group of impending danger. Now, researchers reporting in Current Biology on November 9 have shown that crested pigeons do this in a surprisingly non-vocal way. One of their main flight feathers produces a critical high-pitched sound as the birds fly away. As they flap faster to escape a predator, that alarm signal automatically increases in tempo.

Importantly, the researchers also show that other crested pigeons flee when they hear that sound. The findings confirm that the sound is a bona fide signal, not just a side effect of flight.

"Crested pigeons signal danger with noisy wings, not voices," says Trevor Murray of The Australian National University. "It shows that birds really can use their feathers as 'musical instruments' to communicate with others."

Charles Darwin proposed the idea of non-vocal "instruments" in birds about 150 years ago, but it has been a difficult idea to test. Scientists had long known that crested pigeons make loud sounds when they fly. For that reason, they are sometimes called "whistle-winged pigeons." The Australian National University lab led by Robert Magrath earlier found that other pigeons pay attention to those sounds.

To confirm that the whistling feathers were indeed an alarm signal, in this new study, the researchers shot high-speed video and conducted feather-removal experiments. These studies show that the birds' unusually narrow eighth primary wing feather produces a distinct note with each downstroke. The sound also changes as birds flap faster, such that those fleeing danger produce wing sounds with a higher tempo.

In fact, the birds' wings produce alternating high and low notes in flight. The researchers' experiments showed that the eighth primary wing feather is responsible for the high notes. The low notes come from the ninth primary feather. But, playback experiments showed, only the high notes are critical for sounding an alarm.

When the researchers played flight sounds to other pigeons, individuals were much more likely to flee upon hearing the flight of a bird with an intact eighth primary feather. When they played the sound of a pigeon with that eighth feather removed, they often just looked around instead of taking off.

"We show that the crested pigeon produces an acoustic alarm signal with its wings and that it is an intrinsically reliable signal of danger," Murray says. "The alarm signal is intrinsically reliable because pigeons flap faster to escape predators, and this fast flapping automatically produces the high-tempo alarm signal."

Crested pigeons are not the only birds known to produce unusually loud sounds with their wings, the researchers note. Pigeons in general fly noisily. Hummingbirds and manikins are also well known for their wing sounds. They hope that future studies will explore the evolution of wing sounds in other bird species.

"Birds have such prominent voices, we have largely ignored their surprisingly complex instrumental sounds," Magrath says.
Financial support was provided by the Research School of Biology, the ARC Centre of Excellence program, and the Australian Defence Science and Technology Organisation.

Current Biology, Murray et al.: "Sounds of Modified Flight Feathers Reliably Signal Danger in a Pigeon"

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: To receive Cell Press media alerts, contact

Cell Press

Related Birds Articles from Brightsurf:

In a warming climate, can birds take the heat?
We don't know precisely how hot things will get as climate change marches on, but animals in the tropics may not fare as well as their temperate relatives.

Dull-colored birds don't see the world like colorful birds do
Bengalese finches -- also called the Society finch -- are a species of brown, black and white birds that don't rely on colorful signals when choosing a mate.

Some dinosaurs could fly before they were birds
New research using the most comprehensive study of feathered dinosaurs and early birds has revised the evolutionary relationships of dinosaurs at the origin of birds.

If it's big enough and leafy enough the birds will come
A new study from the Cornell Lab of Ornithology highlights specific features of urban green spaces that support the greatest diversity of bird species.

How do birds understand 'foreign' calls?
New research from Kyoto University show that the coal tit (Periparus ater) can eavesdrop and react to the predatory warning calls of the Japanese tit (Parus minor) and evokes a visual image of the predator in their mind

Microelectronics for birds
Ornithologists and physicists from St Petersburg University have conducted an interdisciplinary study together with colleagues from Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences and the Biological Station Rybachy of the Zoological Institute of the Russian Academy of Sciences.

Birds of a feather better not together
A new study of North American birds from Washington University in St.

Not-so-dirty birds? Not enough evidence to link wild birds to food-borne illness
Despite the perception that wild birds in farm fields can cause food-borne illness, a WSU study has found little evidence linking birds to E. coli, Salmonella and Campylobacter outbreaks.

Birds are shrinking as the climate warms
After 40 years of collecting birds that ran into Chicago buildings, scientists have been able to show that the birds have been shrinking as the climate's warmed up.

Diving birds follow each other when fishing
Diving seabirds watch each other to work out when to dive, new research shows.

Read More: Birds News and Birds Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to