Birds squawk louder to be heard over traffic- evolution in action!
"Hipster bird species evolving to tune out urban sounds", according to Wendy Zuckerman (New Scientist 07 January 2011):
Call them the urban new breed. We know birds raise their voices to make themselves heard in the noisy big city, but for the first time there is evidence that they may even be evolving as a result of city living.Apparently, urban birds sing more loudly to attract mates, and are assumed to be evolving as a result: "The city is pushing these birds to evolve."
"Urban birds might be becoming genetically distinct, which is the first step towards becoming a new 'urban' species," says Dominique Potvin of the University of Melbourne, Australia.
Is it? Another scientist, Hans Slabbekoorn, suggest that it is possible that the birds "might be just calling louder under noisier conditions."
A friend has suggested moving the urban birds to a rural setting and seeing what happens.
Study of birds adapting to urban life is most interesting, but in most cases calling minor changes "evolution" seems a stretch to me. They are probably better seen as the way a hardy species avoids extinction or extirpation via minor, reversible adjustments.
I’d be interested to see what happens to the Toronto area Canada geese who no longer migrate and spend the winter gobbling lawns. In a century, will they otherwise differ significantly from their virtuous rural cousins?
|Canada geese in pond near Ottawa, Wikimedia Cmmons|