Bird Communication Hampered by Noise Pollution

Extant theropods (birds) are having a rough time communicating with each other as man-made noise pollution is getting in the way.  That is the conclusion from new research from Queen’s University (Belfast).  Both urban and rural bird populations could decline as noise pollution prevents effective communication during the mating season.

New Study Suggests Bird Song Badly Affected by Noise Pollution

Picture credit: Queen’s University (Belfast)

Living Theropods Affected by Noise Pollution

In the spring, birds use song to show aggressiveness and to attain territory for nesting and breeding, but this is becoming much harder for them due to noisy conditions created by our own species.  Dr Gareth Arnott, (Senior Lecturer and Researcher from the Institute for Global Food Security), at Queen’s University, studied bird song in detail and found that background noise can mask crucial information.  The scientific paper has been published this week in the academic journal “Biology Letters”.

Commenting on the significance of his study for British ornithology, Dr Arnott stated:

“Sound is a great form of bird communication because it can carry beyond where birds can see.  Singing is one of the most common ways birds advertise that a territory belongs to them, and birds will perch near the edge of their territory to broadcast their claim to the maximum range.  A strong, vibrant song will help defend a territory from intruders and attract a mate.”

The Impact of Noise Pollution

However, Dr Arnott and his colleagues have identified that man-made noise is disrupting birds from being able to hear and understand each other clearly.  In effect, thanks to us, birds are losing the ability to communicate orally with each other, this could have dire consequences in terms of breeding success and subsequent population numbers.

Dr Arnott added:

“We found that bird song structure can communicate aggressive intent, enabling birds to assess their opponent, but human-made noise can disrupt this crucial information passed between them by masking the complexity of their songs used for acquiring resources, such as territory and space for nesting.  As a result, the birds receive incomplete information on their opponent’s intent and do not appropriately adjust their response.”

Testing the Responses of the Humble Garden Robin

To test how noise pollution might be disrupting avian communication, the researchers used recordings of robins (Erithacus rubecula) to stimulate responses from birds that held territory.  Both simple and more complex types of bird song were tested with and without the addition of man-made noise.  The behaviour and responses of the subject birds were then assessed.

The scientists discovered that song complexity was used as a signal of aggressive intent, with birds demonstrating higher aggressive intent towards complex versus simple song, reflecting the level of threat perceived by the signal.  However, importantly, this assessment process was disrupted by the presence of noise pollution.  The team’s findings raise concerns about the ability of birds to cope with a modern, ever more complex human society.

Implications for the Dinosauria

The study also demonstrated that bird song is crucial to the survival and reproduction of birds and there are important implications to consider around noise pollution and the protection of wildlife.  This research may have implications regarding how other extinct types of theropod may have behaved including maniraptoran dinosaurs.

Did Extinct Theropods Vocalise to Proclaim Territories and to Attract a Mate?

Picture credit: Nicole Fuller/Sayo Art for University of Texas at Austin

Dr Arnott concluded:

“The study is evidence that human-made noise pollution impacts animal habitats and directly influences their ability to communicate properly, which may have implications for survival and population numbers for birds.”

Trying to Protect Extant Theropods

The research team believe that further investigation is required in order to help to find the best way to protect avian biodiversity.

The scientific paper: “Signal complexity communicates aggressive intent during contests, but the process is disrupted by noise” by Kyriacos Kareklas, James Wilson, Hansjoerg P. Kunc and Gareth Arnott published in Biology Letters.

Everything Dinosaur acknowledges the assistance of a press release from Queen’s University Belfast in the preparation of this article.

The Everything Dinosaur website: Everything Dinosaur’s Website.