One thing I've noticed is that most birds (hawks excepted, maybe) don't want to tangle with an aircraft, but often appear confused as to what avoiding action to take. (I see this from the tower frequently.)
The moment you start to bank, the bird/s will immediately bank the other way (if they're alarmed) to avoid a conflict. (They probably see it as avoiding a predator.)
This applies to (most) seagulls, anyway, and most other birds I've swerved to avoid.
I doubt it applies to geese. Geese seem remarkably unmaneouverable. I've witnessed a kestrel take out a goose - there were a pair of them in a shallow climb, maybe 300' up, and the predator dived from well above that, yelling it's throat out. I could see the geese 'rubbernecking' and generally looking agitated, but did they try and turn? Not even a degree. The kestrel hit the trailing bird, creating a minor explosion of feathers, and it just dropped out of the sky. We heard the sound of the first impact (from about a km away) as it hit the ground, then the second ground-strike thump. Quite spectacular.
Sully didn't stand a chance.