** Reply to note from tweeters at u.washington.edu Mon, 25 Nov 1996 00:02:43 PST


> All three eagles (2 young Baldies, 1 unidentifiable) were *very* high,
> making me wonder if we're beginning to see the annual move of Baldies out to
> the coast finally underway with the week-long freeze. Though I'm sure
> there's exceptions, and this may be one of them, over the years I've
> observed that the local (Stanley Pk, West Vcr, Point Grey) eagles don't
> usually bother going for extreme altitude, but migrant eagles in the March
> to April movement do.

That migrating eagles fly high there can be no doubt as confirmed by the
Mt. Lorette, AB eagle watches of the past several years. As for resident
eagles shunning high altitudes, this may just be a case of not needing to
find tailwinds. However, I have noticed here in the winter that when there
is a steep inversion, ravens and other birds will often soar at higher
altitudes than usual, presumably to bask in the warmer temperatures aloft.
This would work best when the inversion is sharp and shallow since the birds
could more easily fly above the top of the inversion and thus gain extra
lift from the unstable air above the inversion surface. Such a situation would
have existed in Vancouver as the Arctic air shallowed out this past weekend.

- Jack



Jack Bowling
Prince George, BC
Canada
jcbowling at mindlink.bc.ca