Birds sing shorter songs in response to traffic noise

April 18, 2017
Birds sing shorter songs in response to traffic noise. Credit: Image provided by Dr. Katherine Gentry

Birds sing differently in response to traffic noise, which potentially affects their ability to attract mates and defend their territory, according to research published in Bioacoustics. The study found that a species of North American flycatcher sings shorter songs at a lower range of frequencies in response to traffic noise levels. The researchers suggest traffic noise reduction, for example through road closures, is a viable option for mitigating this effect.

Dr. Katherine Gentry of George Mason University, Virginia, USA and colleagues studied the of the Eastern wood pewee (Contopus virens) in three parks within the greater Washington, D.C. area. Songs were recorded at sites where the traffic pattern of the nearest was either relatively constant or reduced on a weekly basis during a 36 hour road closure.

The bandwidth, duration, and maximum, peak and minimum frequencies of the birdsong was measured and analysed, together with low traffic amplitude within 20 seconds of each song, and full-spectrum background noise levels.

The researchers found that the birds immediately responded to fluctuations in traffic noise by adjusting the length and frequencies of their song in order to improve its transmission. When roads were closed, songs returned to their natural state with broader bandwidth, lower minimum frequencies and longer duration.

Although making adjustments helps get songs across when traffic noise increases, birds hearing the altered calls might not respond as strongly to them, thus reducing the abilities of males that adjust their songs to attract a mate and defend a territory. By offering relief from traffic noise, temporary road closures provide birds with the opportunity to sing the version of their song that optimizes vocal performance, mate attraction and territorial defence.

While a uniform reduction in traffic noise is ideal, road closures are helpful and could form part of an effective conservation strategy, the authors say. This could help halt the decline of the Eastern wood pewee, whose numbers in the Washington D.C. area have reportedly fallen by over 50% in less than 70 years, and could also have a beneficial effect on other species capable of adjusting their signals on the fly.

The study's lead author, Dr. Gentry said: "We found that Eastern wood pewees modified their songs to optimize transmission depending on traffic noise levels. The results confirm that temporary measures to reduce noise, such as weekend road closures, can benefit animals and is a feasible and effective option for managing ."

Explore further: Traffic noise reduces birds' response to alarm calls

More information: Katherine E. Gentry et al, Evidence of suboscine song plasticity in response to traffic noise fluctuations and temporary road closures, Bioacoustics (2017). DOI: 10.1080/09524622.2017.1303645

Related Stories

Traffic noise reduces birds' response to alarm calls

December 28, 2016

Pollution can take many forms—including noise. Excess noise in the environment from sources such as traffic can have negative effects on animals that rely on sound to communicate and get information about their surroundings. ...

Traffic noise increases the risk of heart attack

July 8, 2016

Your risk of heart attack increases with the amount of traffic noise to which you are exposed. The increase in risk - though slight - is greatest with road and rail traffic noise, less with aircraft noise. Such are the conclusions ...

Songbirds sound the alarm about traffic noise

December 1, 2016

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 ...

Birds adjust their singing activity around airport noise

September 8, 2016

Scientists from the Max Planck Institute for Ornithology in Seewiesen have determined that birds near Berlin's Tegel airport, one of Europe's largest, start singing significantly earlier in the morning than their counterparts ...

Clamorous city blackbirds

January 11, 2013

(Phys.org)—Animals have developed a variety of strategies for dealing with increasing noise pollution in their habitats. It is known, for example, that many urban birds sing at a high pitch to differentiate their song from ...

Recommended for you

New discovery: Common jellyfish is actually two species

November 21, 2017

University of Delaware professor Patrick Gaffney and alumnus Keith Bayha, a research associate with the Smithsonian's National Museum of Natural History, have determined that a common sea nettle jellyfish is actually two ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.