Cliff Drake wrote:
>> Overwintering in the Puget Sound area, at least in such predictable
>> numbers, is an artifact of our feeding them. And once you start, one
>> is therefor obliged to keeping up a good "hummer cafe".
>>
> I'm not sure I believe either point. There are Anna's in my yard because
> I have a feeder out but if I didn't they'd just go down the block, not
> to Mexico or wherever. I just can't believe our use of feeders has led
> to the Anna's Northward migration. I had a 10 minute chase this morning
> around the house, lots of action in front of the windows. Pretty cool.
> ====================
> Cliff Drake
> Seattle WA (Ballard)
> cliff at cliffdrake.net
>
I checked some sources on this. Cornell's Birds of NA Online had the
most information on migration, but that wasn't much. The discussion
centered on the fact that the major Anna's population is in southern and
central California. Post-breeding the birds move up into the mountains,
east into Nevada Arizona and "north up the coast." None of the other
sources (Sibley and Audubon Guides, a few ".edu" Web sites) say much
more than that the species has been expanding since the 1950s,
especially to the north. It has always been my understanding that our
Anna's population stays around all winter eating arthropods with feeder
nectar as dessert, but that's received info not science. It has been my
impression that there are more Anna's around here in winter than in
summer, but that may be because the trees are bare and the birds
therefore more visible. Is it possible that our winter population is
supplemented by migrants from the Great White North? Anyway, as someone
else remarked, it's nice to have the color around in winter.

Dale

--
Dale Chase
(AKA ravenintherain)
Seattle, Washington
ccorax at blarg.net