Tipiwoo:
Which is where the cats found them scarfing down the rice.
Seriously, considering how long people in this country have been throwing rice at newlyweds, don’t you think that someone would have noticed large numbers of dead birds surrounding churches sometime before it became a UL in the 1970’s? Think of the local Italian parish where they were cranking out four to six weddings every Saturday in the late 1960’s as the first boomers grew up (or the same location at the end of WWII when the first boomers were being (pro)created). Those places would have been hip dip in dead birds by the end of June each summer. (And why is it that Southeast Asia, Louisiana, and East Texas do not have a serious dead bird removal problem at the time of the rice harvests?)
I suspect that the dead-birds-after-weddings that you saw were simply coincidence–or there are often dead birds around tall buildings and you have simply noticed them more after you know a wedding has taken place.
Tom~