As to Michael Atzeni's question as to why swift migration down south is so
unswift: I guess the reason is that this migration is a migration to
wintering quarters, not to breeding grounds. I don;t doubt that once the
correct date comes round the swifts start off very rapidly north for their
breeding grounds, because they have to get there, breed, get their young
flegded, and get away again before the next autumn. But when they're flying
south it's more of leisurely wander along the Great Dividing Range, and the
only incentive for them to move at all is the possibility of better numbers
of insects beyond the next range, or whatever.
Some birds are in just as much of a hurry to get south as they are to get
north because they must moult when they get there, but I'd think that swifts
must moult a few feathers at a time, and so once again there's no hurry for
them.
John Leonard
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