Sunday, October 25, 2020

Birdsong, Freeways and the Pandemic.

Environmental & Science Education, STEM, Nature, Biological Diversity, Behavior

Ed Hessler

I look forward to Jim Williams's weekly columns in the StarTribune on the world of birds. I'd known for a long time that birds are negatively affected by traffic noise,especially the steady buzz, whine, hum and thunder of "freeways." 

High sound levels from traffic degrade bird habitat leading to population declines. Owls hunt by sound and birds establish territories and home range through their voices. These behaviors are overwhelmed by traffic noise. The area is known as "a road-effect zone," which in one study "was approximately 360 yards wide." The counterparts of birds living in rural areas don't contend with this and can sing more softly as well as sing more complexly.

This week, Williams reports on research published in Science (AAAS) led by "Elizabeth Derryberry, a behavioral ecologist at the University of Tennessee...(that birds) seemed to react to the drop in human noise (during the pandemic). ... After decades of sacrificing song quality for higher volume, (white-crowned) sparrows have switched to songs that closely resemble those of rural cousins. Those are the songs all white-crowns sang in our previous world." 

The research was conducted in San Francisco, the site of previous studies. You may read Williams's column in the Star Tribune here. I always add a please do--you will miss details that are important. And it is short without depriving you of some of the riches of such studies. It also includes a lovely image of a white-crowned sparrow, a handsome bird if ever there was one.

Williams ends ominously. "In the continental U.S, more than 80% of our land is less than a mile from a road In the next 30 years 15 million miles of new road are expected worldwide."

Thanks again, Mr. Williams.

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