Mac-
I don't know what kind of birds you have, but I might have a
suggestion. At Home Depot or other garden centers, you will often find
fake owls available for sale. They are provided to help run off most
birds.

My daughter had trouble with birds attacking her apricot tree just
before harvest. And, she was losing an awful lot of fruit to them.
She put out one of those owls, and voila' many of the birds went
elsewhere.

I've seen little sidewalk cafes that have these same owls in the
overhangs and on roofs, and it keeps their diners from being bombed.

There are also little devices you can purchase that make the sounds of
preditary birds, and runs off most other birds. But, they can be
pricey, and the sound can be annoying.

Hope this helps!

Myrl Jeffcoat
http://www.myrljeffcoat.com