Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clamorous city blackbirds

14.01.2013
Birds can sing louder at higher frequencies and thereby make themselves heard in traffic noise

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 the low-frequency sound of road traffic.


Blackbirds also find an abundant food supply in the city. © Michael Dvorak

However, as scientists from the Max Planck Institute for Ornithology discovered, this is just a useful side effect. The real reason for this behaviour is that songs at a higher pitch are also automatically louder. The birds can make themselves heard far better in city noise by increasing the volume of their song than by raising its frequency.

Despite the numerous unfavourable environmental conditions they encounter there, many wild animals have colonised cities as a new habitat. In cities they must deal with greater numbers of humans and with more light and noise pollution than they encounter in rural settings. However, the urban habitat also offers certain advantages, for example a more abundant supply of food and new breeding options. Many animals have thus adapted surprisingly well to city life.

To attract mating partners and defend their territories, urban robins sing in the latter night when the traffic noise decreases after the evening rush. Many other bird species, including blackbirds, sing in urban environments at a higher pitch. So their song is easier to detect in the lower-frequency traffic noise.

However, as a group of scientists from the Max Planck Institute for Ornithology in Seewiesen and Radolfzell has discovered, this is just half the truth. They studied urban blackbirds in the city of Vienna and country blackbirds in the nearby Vienna Woods. Additionally, they raised birds by hand at the Max Planck Institute and investigated the correlations between the frequency and amplitude of their song under controlled conditions. It emerged from this research that the animals were able to produce higher tones at higher amplitudes. In the city, blackbirds sing preferably at these high frequencies that they can produce particularly loudly.

In a further step, the researchers examined which effect is better suited to avoiding the acoustic masking by traffic noise: the higher frequency or the higher amplitude that results from it. “The higher volume of the higher-pitched song is more effective than the higher frequency,” says Erwin Nemeth, first author of the study. “So we assume that the increased volume is the main cause of the higher frequency singing by city birds.” Henrik Brumm, the leader of the research team, adds: “By actively selecting high-frequency sounds, the city birds can increase their capacity to sing loudly and in this way counteract the acoustic masking of their song by the ambient noise.”

Contact

Dr. Henrik Brumm,
Max Planck Institute for Ornithology, Seewiesen
Phone: +49 8157 932-355
Email: brumm@­orn.mpg.de
Dr. Erwin Nemeth,
Research Group Communication and Social Behaviour
Max Planck Institute for Ornithology, Seewiesen
Phone: +43 664 4568-191
Email: enemeth@­orn.mpg.de
Dr. Sabine Spehn,
Press and Public Relations Seewiesen
Max Planck Institute for Ornithology, Seewiesen
Phone: +49 8157 932-421
Fax: +49 8157 932-209
Email: pr_seewiesen@­orn.mpg.de
Original publication
Erwin Nemeth, Nadia Pieretti, Sue Anne Zollinger, Nicole Geberzahn, Jesko Partecke, Ana Catarina Miranda and Henrik Brumm
Bird song and anthropogenic noise: Vocal constraints may explain why birds sing higher frequency songs in cities

Proceedings of the Royal Society B. Published online January 8, 2013 doi: 10.1098/rspb.2012.2798

Dr. Henrik Brumm | Max-Planck-Institute
Further information:
http://www.mpg.de
http://www.mpg.de/6814595/city-blackbirds-traffic-noise

More articles from Life Sciences:

nachricht Nonstop Tranport of Cargo in Nanomachines
20.11.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Researchers find social cultures in chimpanzees
20.11.2018 | Universität Leipzig

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>