Pigeons Sound the Alarm with Whistling Feathers

By Charles Choi | November 9, 2017 12:00 pm

When the crested pigeon of Australia flees potential foes, it can raise an alarm — not by calling out vocally, but with whistling feathers in its wings. These new findings may be the first proof of an idea Darwin proposed nearly 150 years ago suggesting that birds could use feathers as musical instruments for communication.

Birds are known for the songs they can sing, but many can also generate unusual noises with their feathers. Darwin called these sounds “instrumental music” in his 1871 book exploring the role of sex in evolution. For instance, “peacocks and birds of paradise rattle their quills together, and the vibratory movement apparently serves merely to make a noise, for it can hardly add to the beauty of their plumage,” Darwin wrote.

Feathers are known to produce distinctive sounds in at least 70 different species of birds, with many of these plumes possessing highly modified structures apparently specialized to make these noises. However, it was difficult to prove whether birds communicated with each other with these sounds.

For instance, scientists have long known that crested pigeon wings whistled when the birds flew. However, one could argue these noises were “unintentional byproducts of flight, rather than signals that have evolved for communication,” says study lead author Trevor Murray, a behavioral ecologist at Australian National University in Canberra.

Continued  

Songbirds sound the alarm about traffic noise

Date: November 30, 2016

Source: Pacific University (Ore.)

A new study led by Pacific University biologist Chris Templeton demonstrates that the alarm calls of songbirds are dramatically impaired by road traffic noise. Research by Templeton and colleagues has shown that signals critical for the survival of animals are compromised when birds live near even moderately busy roads.

The study appears in the Nov. 21 edition of Current Biology, and notes that "failure of species to detect anti-predator signals could have significant negative consequences for animals living near roads and other sources of anthropogenic noise."

Previous research strongly suggests that noise pollution impacts the ability of birds and other animals to effectively transmit information in their courtship signals. Templeton and his colleagues' findings look at the impact that noise generated by nearby vehicular traffic has on the ability of birds to alert one another of impending danger, such as the presence of predatory species. "When a bird of prey like a hawk or owl is discovered, many species of birds produce alarm calls to warn other individuals in their flock of the impending danger," Templeton said.

In collaboration with Sue Anne Zollinger and Henrik Brumm (Max Planck Institute for Ornithology, Germany), Templeton examined how traffic noise affects both how birds produce alarm calls and how other individuals in their flocks respond to them. He and his team researched the behavior of a songbird species named the great tit (Parus major).


Continued