[Tweeters] September Snow Geese (was Tweeters] off-topic RFI Cape Town)

[Michael Price]

Hi tweets

When I saw two subadult Snow Geese passing over Pt Grey on Vancouver BC's
west side in week 4 some years ago, I thought them anomalously early. Turns
out that southbound SNGO average arrival in Vancouver BC is *Sept *23,
first birds back almost invariably as subadult pairs, with the first large
*flocks* arriving week 2 October. Go figure.

Same thing with Rough-legged Hawks and mid- and late-August sightings. Not
a fluke. I remember reading an article on the 'unusual' but regular pattern
regarding RLHA (kinda like the annual 'freak blizzards' every May on the
Prairies), but I forget the proposed mechanisms which get the immature
hawks south so far in advance.

This is the reverse of shorebird migration in which the southbound arrival
of most adults precede the precocial juveniles by three to four weeks on
average. The exception being Bar-tailed Godwit, where southbound adults
arrive on this coast at these latitudes usually in late July but the
juveniles don't usually appear until Week 1 October, two *months* later.
But that's another thread, possibly involving two very separate BTGO
populations.

best, m
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