There is a thread I started back in Jan on different types of blueberries if you do decide to buy one. I haven't had a chance to get one yet, so I can't help you with your droppings question.
http://forums.gardenweb.com/forums/load/pagard/msg011821122326.html

Thank you Nick!
I'll check it out!

Hello,
In response to your question, we have successfully had our first "splat-free" summer with wonderfully-productive lucious blueberries. We planted the highbush blueberries several years ago, and this year was a bumper crop. We planted a variety, (high and low- Coville, Jersey, Earliblue) but the names of those that did the best were the highbush Jersey. Last year we had more berries, but did not cover the bushes and the birds did eat most of them and left messes. It helped immensely that we put a netting over all the bushes and we had not had any bird problems this year (eating the berries or making messes).
Hope this helped.
Heather, Central PA
Shamrock_Boxer