[Science] Noise pollution forces Canadian songbirds to change their tunes

[tao]

Some Canadian songbirds have to change their tunes because noise pollution from things like oil and gas drilling equipment otherwise drowns out important parts of their songs, University of Manitoba researchers have found.

 

 

Birdsongs carry information, like how fit or "sexy" the singer is, the species, even the individual's "name" and motivation. Miya Warrington and Nicola Koper from the U of M's Natural Resources Institute looked at what parts of the birdsongs were changing to learn what aspects of their song are most under threat of being drowned out by noise.

 

"Birdsong, in a sense, may act as a 'message in a bottle', indicating how a bird may be struggling in terms of communicating their messages to their fellow birds," Warrington says.

 

The U of M team published their findings in this month's The Condor: Ornithological Applications. They showed that the Savannah sparrow is able to adjust their song in subtle and precise ways to cope with noise pollution from natural gas well and oil extraction infrastructure in their grassland habitat.

 

The birds conduct their songs to account for what oil drilling machines roar at the time, sometimes changing its pitch, sometimes its tonality, to make sure the key nugget of information gets across. For instance, when generator-powered screwpumps scream, males use buzzier notes to say "I'm Sexy," but seemed to have little need to alter their songs when near the quieter types of oil wells, such as those without generators.

 

"Bird song is a complex vocalization that conveys different types of information. It isn't really surprising then that birds may compensate for which ever important piece of information cannot be heard clearly above noise. It's like having a conversation at a loud cocktail party; you may repeat your name several times if that is what is important to you at the time," Warrington says.

 

This also has important conservation implications. Grassland songbirds are declining faster than songbirds in any other ecosystem in North America, and activities from energy extraction may be further threatening vulnerable species.

 

"Our soundscapes are changing, just as our landscapes are changing," says professor Nicola Koper, who supervised the research. "Different species have all sorts of ways of compensating for this. It's fascinating to me that Savannah sparrow's response to noise is so subtle and precise. I just hope their techniques are effective – that's what we are looking at next."

[...]

 

If interested, please read the full article < here >.