Coping Mechanisms : Birds and Industrial Noise

"It's something that is really picking up, the idea of noise pollution. We want to see what is that doing for the birds."
"You can hear birds clearly when it's quieter. When you're closer to the infrastructure, you don't hear the birds as clearly. You start to think, if I can't hear, maybe the birds can't hear."
"The birds are modifying their birdsong in response to the noise that's created by this oil and natural gas infrastructure."
"They've actually been looking at a whole lot of grassland species and finding that, in some species, the presence of oil infrastructure is affecting reproduction while in others it's not."
Miya Warrington, researcher, University of Manitoba

A Savannah sparrow sits on a post with Calgary in the background. (Eduardo Matoud)

In the most recent issue of Condor, the journal of the American Ornithological Society, there were several interesting papers. One set out to determine how grouse, a ground bird, adjust their mating calls in the presence of sound emanating from now-ubiquitous wind turbines. The conclusion was that these birds like many others have raised their songs a pitch or so as a result of living in city environments which tend to be noisy and disruptive to the birds' normal rhythms.

The bird research world is fully engaged now in this topic: avian response to human-generated sound.

This is proving to be an existential issue for some birds such as sparrows, particularly at a time of universal stress for songbirds now in decline -- and grassland species are proving to have surrendered to the swiftest decline of all. Attention has focused on the sound pollution affecting Savannah sparrows, a small, common sparrow with a thick beak and a yellow patch over its eyes. It has a complex song with various "syllables", each transmitting information of importance to others of its species.

Parts of the sparrows' song relates to territorial warnings while others invite the presence of potential mates. Others yet announce "I am here", but whatever the message, they all represent critical areas of the bird's survival and each bird has its own special version of the song; sounds that range from trills to buzzes. What has been complicating the lives of these sparrows is the presence on prairies where the birds are to be found in their natural habitat, of noisy machinery such as oil and gas infrastructure located on the plains.

For her research, Miya Warrington brought in 26 sites around southern Alberta where she would collect data; sites with four types of energy infrastructure inclusive of natural gas compressors, pumpjacks, screw pumps powered by electricity on the grid, and screw pumps generator-powered. The songs of 73 male sparrows were accordingly recorded and analyzed between May and July, to compare them with the songs of sparrows resident where no oilpatch facilities exist.

The resulting analysis concluded that all the pumps and compressors produced sounds on the  same frequencies as those of at least a portion of the songs produced by the sparrows. The recordings, furthermore, revealed how the birds coped with this interference, by adjusting parts of their songs, reflecting the source of the background noise. According to the paper: "All syllable types were significantly affected by at least one infrastructure type".

Savannah Sparrow - Claude Rioux

In response to the ambient noise interference within the habitat of some of the birds studied, it was recognized that birds effected alterations in their songs to enable them to be heard over the equipment noise; in some instances sparrows' songs were entirely produced at higher frequencies, reflecting a transposition to a higher key. It was also found that of the four types of infrastructure involved, it was the generator-powered screw pumps that produced the most disturbing impact, natural gas compressors having the lightest.

Pumpjacks pump crude oil near Halkirk, Alta., June 20, 2007. Noisy oilpatch equipment is causing songbirds to change their tune, concludes a new research from the University of Manitoba. Larry MacDougal - The Canadian Press, 2018