On a more data-driven note, I was wondering how bad the birdstrike problem actually was, so I went here:
http://www.lrbcg.com/nwrcsandusky/Strike.html
2,500 incidents per year in the US. Happily, most cause no damage (other than a dented wing I guess). But most strikes happen in daytime during takeoff or landing - so even circuits in a C150 aren't immune.