I'd like someone to sit on my deck on 24th st and clean the di

Avalon - I'd like someone to sit on my deck on 24th st and clean the diarrhea party the birds had on my deck. Everyday, clumps of bird feces on everything. I live near restaurants but I was here many years before them. If there is a humane way to keep them away, please tell. If not stop over for lunch on the deck, wear a wide brimmed hat!