Geez, I feel so bad for you folks that have to go through the buzzards!! We have eagles here, and they show up every year at calving time -- they know the drill, and we are near the river -- they are after after-birth. They don't tear into live babies.
This is a very cruel (in my mind), but effective way I've heard to bait pest birds. And if we had your problem, I'd do it. Find a high tree; or put up a high pole. Hang heavy duty trebel hooks on light cable, baited with meat. Then sleuce them where they hang.