Thanks to everyone who got back to me on- and off-list about yesterday’s corvid drama in my backyard. The large audience of crows and ravens appeared to lose interest after a little over an hour and drifted away, and the two combatants separated and flew off about ten minutes later. I went out and looked at the battlefield - no blood, only one feather. I guess the whole thing was more akin to arm wrestling than Ultimate Fighting Machine!
The crow videos recommended by Hilke are truly wonderful!