The young snow goose at the end of the first episode. Left behind by its flock, it is attacked by a bald eagle. One might expect it to meet its demise then and there, but it manages to avoid the eagle's initial attack while slipping and sliding on ice. It then attacks the eagle, holding it off long enough to get itself into the air. The eagle strikes yet again as the snow goose tries to fly away, but the goose dodges and successfully makes its escape.
The vultures in the second episode gather in such huge numbers around a lion that the lion gets irritated enough to try and chase them off. Eventually the lion is forced to chase them away so many times that it has to seek shade to avoid overheating, allowing the vultures to move in and feed on its kill.
The African fish eagle in the second episode fighting off a marabou stork, a much larger bird that could have impaled it with one jab.
The crows in the third episode showing up out of nowhere and chasing off a golden eagle that had been about to attack some barnacle geese.
And in the fifth episode, crows also save some pigeons from a steppe eagle.
The barnacle geese, arctic terns, and skua divebombing and driving off a marauding polar bear.
The Japanese cranes in the fifth episode defending themselves from sea eagles.
The sheer size of the budgerigar flock in the fifth episode. And if that weren't enough the flock is shown to be maneuverable enough to dodge attacks from two black falcons, to the point where individual birds can drink at intervals while in evasion formation. Just to drive the point home, at one point when one of the falcons manages to isolate a single budgerigar, the budgie outflies the falcon and melds back into the flock. The two falcons return to their tree empty taloned.
The footage. From a bird's eye view, one can view the curvature of the Earth and the full extent of a rainbow.