Tweeters,

The question asked by Greg Gillson in the attached message from OBOL
(late departures or early arrivals?) has been asked by some on
TWEETERS as well. We went through a very similar discussion last
winter about January
and February sightings of BARN SWALLOWS. My contention is that most
of these birds were neither late departures nor early arrivals, in the
context of normal migration patterns. Rather, they seem to be part of
a mid-winter northward push which appears to be partly weather-related
and partly a result of active movement by the birds.

There were widespread reports of BARN SWALLOWS, sometimes accompanied
by a few TREE or VIOLET-GREEN SWALLOWS, throughout western Oregon,
western Washington, and southwestern B.C. (lower Fraser Valley),
starting about January 10 to 12, 2003. (One CLIFF SWALLOW was also
seen on January 12 in Langley, B.C.) There were enough reports that I
suspect that hundreds of swallows may have been involved in total.
Most of these (except for Florence, OR, where there were 20 on the
CBC) were in areas where few or none had been seen in December or
early January. If the patterns established in past winters are
followed, most of these will disappear by late February or March, and
few Barn Swallows will be seen until the normal arrival dates in early
April.

The discussion above applies mainly to BARN SWALLOWS. Tree Swallows
and Violet-greens have different migration patterns, and normally
arrive in most of the Northwest in the latter half of February and
March.

This mid-winter invasion of Barn Swallows has been evident, to one
degree or another, in every one of the last 5 winters. The causes are
still a mystery-- possibly some combination of weather patterns and
abnormal movement by the birds? However, because Barn Swallows are
rare even in southern California in winter, I suspect that some of
these birds came all the way from Mexico.

Keep on reporting those mid-winter swallows!

Wayne C. Weber
Kamloops and Delta, BC
contopus at shaw.ca


----- Original Message -----
> From: <greg.gillson at exgate.tek.com>
> To: Obol <obol at lists.orst.edu>
> Sent: Wednesday, January 22, 2003 3:03 PM
> Subject: [obol] swallows late? or early?
>
>
> > A check of the Western bird e-mail lists found BARN SWALLOWS from
> Monterey
> > to British Columbia in the last couple of weeks. No reports from
> southern
> > California or Arizona (except one report on the Blythe CBC on the
> lower
> > Colorado River around New Year's Day). This suggests to me that
> these birds
> > may be wintering (April 1st is about the time to expect the first
> Barn
> > Swallows in the Willamette Valley). At the very least, they don't
> SEEM to be
> > migrating, or I would expect more reports from farther south.
> >
> > VIOLET-GREEN SWALLOWS are being reported from SE California and
> Arizona.
> > They are evidently starting to move north.
> >
> > Reports of TREE SWALLOWS are widespread on the West Coast, but in
> low
> > numbers.
> >
> > A birder from San Diego reported an unidentified "pale-rumped"
> swallow last
> > week on the San Diego list and asked 'early migrant or lingerer?'.
I
> guess
> > we're not alone.
> >
> > Greg Gillson
> > greg at thebirdguide.com <mailto:greg at thebirdguide.com>
> >
> >
>