Swallows may be evolving to dodge traffic

[Sagan]

by Beth Marie Mole

Roadside-nesting cliff swallows have evolved shorter, more manoeuvrable wings, which may have helped them to make hasty retreats from oncoming vehicles, according to a study published in Current Biology1.

The study’s authors discovered the trend after noticing that the number of vehicle-killed birds had declined over the past three decades. They suggest that the two findings provide evidence of roadway-related adaptation.

“I’m not saying that it’s all because of wing length,” says Charles Brown, a biologist at the University of Tulsa in Oklahoma and one of the authors of the study. But, he says, the shortening does support the idea that the birds are adapting to disturbed environments, as other organisms presumably are.

Together with Mary Bomberger Brown, a ornithologist at the University of Nebraska–Lincoln, Brown tracked roadside populations of cliff swallows (Petrochelidon pyrrhonota) in western Nebraska for 30 years, mostly to study the birds social behaviors within their colonies.

more
http://www.nature.com/news/swallows-...raffic-1.12614

[merc]

i find this fascinating. In the parking lot where I work, it's lit up by street lights and some birds seem to hang out singing and searching the ground for food all night long. I think they have adapted to a more nocturnal existence due to this.
Also, the cardinals at my feeder aren't as red as the ones I see in photos. They have really drab backs very gray or black and their fronts are red, kind of similar to a robin and I think it may be due to the amount of hawks, a darker drab bird is less easy to see.