Bluffing the bully

I had to laugh. It was David and Goliath, the wimps outwitting the bully.
Last week all of the Swamp Gums Eucalyptus ovata in the bush at Homerton were covered in blossom and the birds were out and about to take advantage-numerous flocks of lorikeets and honeyeaters. In one part of the bush each of the flowering trees had a resident Red Wattlebird noisily defending its food supply.
I watched in amusement as a flock of White-naped Honeyeaters used a great strategy to grab a snack on their way through the canopy. They would land as a flock in a Swamp Gum, and as the 'resident' wattlebird flew madly around the canopy ejecting them one at a time the rest of the flock would be on the other side of the canopy having lunch. After a few minutes the whole flock would then move off to annoy another wattlebird.
I wonder what the signal is for the whole flock to move on? And is there a boss bird that decides which tree they're going to descend onto next?