Good information on what to do. Thanks, Mona!
As for preditor birds in the big city, don't feel secure ~just~ because you are in the city.
In Cleveland, OH on the Terminal Tower right on Public Square (the heart of Cleveland) there was a family a Peregrin Falcons for some 12 years. This has been followed by researchers from the very beginning. It was big news when the female got challenged by a younger female and lost (died from her injuries) and became the new mate for the male. This past year the male died from head injuries. Those who were monitoring the falcons maintained that the male sired 34 chicks total between the two females. Some of their young set up nests also in the heart of the city on other highrise buildings.
Want proof? Check this out:http://blog.cleveland.com/metro/2009/11/post_132.html
I have personally seen a Bald Eagle on two different occasions and more Hawks (Red Tailed, Cooper's, and even Red Shouldered) more times than I can count in greater Akron (another big Ohio city).
Bottom line: Birds don't necessarily need trees to survive.
P.S. I was an outdoor birder before becoming an indoor one!