YouPeopleAreCrazy: Camera on a tripod, video at 480fps, a video of some average sparrows doing their thing at the feeders.
Not until I watched the vid later did we see the bloodthirstyness and fighting skills.

One of the funniest nature scenes I've ever seen was at my 6 station bird feeder. A bossy house finch parked himself there for about 10 minutes, hopping from station to station chasing all the other birds away, losing WAY more time in the process than if he just quit it and ate at "his" station. During that show, a red-bellied woodpecker was following his normal process of swooping in to an open station, grabbing one seed, and flying back to his tree to crack/eat. After the finch had cleared out the whole feeder, he noticed the woodpecker "taking too long" to find a seed on one of his trips, and hopped over to the adjacent station and started squawking at the woodpecker 5 times his size. The woodpecker actually leaned back and cocked his head like "are you serious?" for a second, then nailed the finch in the face so hard the finch did a backflip on his way off the feeder.

30 seconds later, all 6 stations were occupied by different birds minding their own business.