From: "Bowling,Jack [PYR]" <Jack.Bowling at ec.gc.ca>
To: "'tweeters at u.washington.edu'" <tweeters at u.washington.edu>
Ned asked -

>With this particularly inclement weather approaching, have any of you folks
>experienced any patterns of bird behavior (unusual or less likely
>sightings) potentially explained by this kind of weather (or other more
>severe oncoming storms)? I'm particularly interested in NW Washington,
>but all comments are welcome and appreciated.

>Where, what, when, bla bla bla? Thanks.

To paraphrase your question: are patterns of bird distribution affected by
the short term weather?

I am sure everyone of us would agree that this is so. Separating shorter
term effects from longer term climatic shifts is more difficult.

For B.C., there are some "golden rules", though:

- appearances of vagrants from Siberia ("Sibes") in autumn and winter are
favored by cold northwesterly flows (makes sense); the corollary to that is
*not* to expect them in inordinately mild winters (such as 1997/98).
- a cold Arctic airmass settling into the interior will usually drive
Red-breasted Sapsuckers and other less cold tolerant species out to the
coast.
- expect to see birds wintering farther north than usual in mild winters.
- in winter, a strong westerly jetstream accompanied by an active storm
track and associated strong low pressure systems pushing onto the coast will
often lead to "wrecks" of birds which routinely winter in the Gulf of Alaska
e.g., phalaropes, storm-petrels, etc. The longer the upstream fetch and the
more prolonged the storm activity, the greater the incidence of wrecks. Note
that this would also be the case if this occurred in summer but both
affected bird species and strong storm tracks are lacking during the warm
months. Due to surface wind patterns, most of the wrecks occur within
100-200 km south of the jetstream. Also, the "Pineapple Express" has its
upstream origins in the Hawaii area which is too far south to drag a lot of
birds up, i.e., the more southern parts of the N. Pacific are more
depauperate of birds than the northern sections in winter, so expect fewer
wrecks in southwesterly flows than westerly or northwesterly ones.

Those are a few of the more conspicuous ones.

- Jack Bowling

writing from Dease Lake, BC 58,30N 130,02W, currently at a balmy minus 7
Celsius
direct replies to jbowling at direct.ca