Field researchers collected 29,842 dead birds outside the exhibit hall from 1978 through 2001. There were 140 different species.
The most common birds included the song sparrow, 3,968; the dark-eyed junco, 3,393; swamp sparrow, 2,987; white-throated sparrow, 2,257; hermit thrush, 1,322; fox sparrow, 1,165; ovenbird, 1,154; American tree sparrow, 986; Lincoln's sparrow, 915; and the Tennessee warbler, 871.
Every Flick Counts
Partly as a result of the Field research, Chicago has started a program called "Lights Out," aimed at reducing unnecessary lights. It isn't always easy, because some buildings are wired in such a way that lights cannot be selectively turned off, but Stotz says most building managers seem eager to cooperate whenever it's possible.
Even turning off some lights, he says, helps a lot.
"Our study indicates that if you turn off some of the lights, you get proportional benefits," he says. "So it's not like if you don't turn off all the lights, it's not worth turning off any of the lights. If you can turn off half the lights, you should cut the number of birds more or less by half."
It doesn't seem like a difficult thing to do, in most cases. And our fine feathered friends can use all the help they can get these days. They've got a tough way to make a living.
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.