I remember fighting the Upland Goose flocks at Stanley (stupid birds) ... oh, hang on, this is off-Topic.
Anywaaaay ... it seemed that if I fired a bird-scaring cartridge into the flock, they would flutter about a bit and then resume their normal pecking. However, a quick reload [or 2 Very pistols ... yay, 6-gun McGraw!] with a cartridge into the middle of their fluttering would actually get the bloody things to go away [for a while].
And now we resume normal programming.