Photo credit: 42 North
by Arline L. Bronzaft, Ph.D., Board of Directors, GrowNYC, Co-founder, The Quiet Coalition, and Honorary Chair, Quiet American Skies
The fact that traffic noise is harmful to humans has been discussed at length in this blog, but this post will inform readers that the harsh sounds of traffic also have long-term negative effects on the health and well-being of birds. Guardian reporter Sofia Quaglia writes that prior research has already found that noise is linked to poorer communication among birds. In this story, she covers new research that explores the impacts of city traffic noise on bird eggs.
Dr. Mylene Mariette and her co-author conducted a study that exposed one group of zebra finch eggs to silence for five days, a second group to zebra finch songs and a third group to traffic noise recordings. In addition, the researchers exposed newborn chicks to the same conditions for up to 13 nights.
When exposed to traffic noise, bird eggs were 20% less likely to hatch, and the newborn chicks exposed to noise were smaller and weighed less. Even though these chicks were no longer being exposed to traffic noise, the earlier exposure lasted into the later years and made them less likely to reproduce. The birds exposed to noise produced fewer than half as many offspring as their study counterparts.
The researchers were surprised that the noise exposure, which they did not consider especially long, led to such strong results. However, these results were questioned by Professor Hans Slabbekoorn, an acoustic ecologist who had similarly exposed chicks to moderate noise levels but found no impact on their growth. Slabbekoorn offered an explanation for the different results in that the parents of the chicks in his studies may have “compensated for the negative effects of the noise.” He added that in his studies, where he examined birds exposed to loud aircraft noise, he found that the birds appeared to be partially deaf.
Undoubtedly, more studies need to be conducted to get a clearer picture of the impact of transportation noise on the health of birds. But, the studies cited in this article do appear to suggest that birds, like humans, are likely adversely affected by transportation noise.
