Cool shot! -I googled a few sites on "scavengers/ birds" and one site did a study in eastern Poland in 2001: (http://www.zbs.bialowieza.pl/publ/pdf/1393.pdf); -RAVENS, then foxes and finally wolves were the three most common scavengers of bison in this study; interesting fact was how long it took to reach 80% clean up of the carcasses (106 days); also interesting, was that wolves were the most important element, for most others were dependent on them to open up the tough carcass.