I like this little mystery presented by the Southern Rockies Nature Blog: Bloody birdfeeder in need of crime scene reconstruction!
Naturally as a falconer my initial response is hawk attack, most likely a Cooper's, but that's some pretty good blood coverage, a quick snatch and dash like a Cooper's would perform wouldn't leave that much blood, would it? And if it was a hawk that caught and ate a bluejay (see note about a single blue jay feather) there would be lots of plucking involved so there would be more feathers...Although he does say there are lots of squirrels that frequent the feeder too...Red-tail pounding a bushy-tail? Don't know that the feeder itself would survive such an attack. Are there ground dwelling possibilities? Coyote?
I dunno, what do ya'll think?? (Maybe comment over on the other blog...it's his mystery not mine! :-)