The changing natural world at our doorsteps | Illustration and text by Patterson Clark
First morning song of American robins in Lyon Park
DURING BREEDING SEASON
*The half-hour before sunrise or after sunset; car headlights are generally not required.
March 27, 2012
American robin song
It takes a night owl
to beat the early bird
Although city noise might play a role in that — an early start helps urban birds avoid the din of rush hour — it's more likely that they are responding to light pollution.
In '29 the first robin songs began about 45 minues before sunrise, but 74 years later, when Lyon Park nights were awash in electrical light, robins tended to break their silence more than an hour earlier, often before any hint of dawn.
Miller's study also included robins near the White House, in an area with even higher levels of artificial light. Those robins began singing about 3 hours earlier than the '29 Lyon Park robins.
Miller said that the starting times for White House robins might be even earlier, because sometimes they were already singing when he arrived to monitor them.
SOURCES: Mark. W. Miller, University of Alaska at Fairbanks; "Apparent Effects of Light Pollution on Singing Behavior of American Robins," the Condor; Biology Letters, the Royal Society