Subject: Xantus' Hummer
Date: Feb 11 22:07:54 1999
From: Michael Price - mprice at mindlink.bc.ca


Hi Tweets,

Sherry Hagen writes:

>Some seem to assume that if this bird, the Xantus hummingbird came up the
>coast somehow or another that someone would have seen it. I ask why? We all
>know that ALL birds are not seen ALL the time by someone. It seems funny that
>a bird like the Brambling can show up in Portland and no one has reported it
>along its path from where it came from. Is there not a chance that this bird,
>the Xantus came up with say, a rufous hummingbird or such. It could have been
>in Alaska all summer and no one saw it til it tried to follow the rufous and
>stopped in Gibson's. Just my two cents and it's free.

A Wrentit is visiting a suet feeder at Sag Harbor, Maine; if accepted, it
will be a first record away from a narrow strip of California and southern
Oregon.

A Californian endemic, a Yellow-billed Magpie, is seen and photographed
picking over discarded offal near a meat-packing plant beside Hudson's Bay
in northern Quebec.

A Catalina Island Scrub Jay appears with Blue Jays on a feeding table just
outside Savannah, Georgia. There are no known records of this species away
from Catalina Island off the California Coast.

In some magic way, you are a member of the rarities committee of each
location. Each committee's constitution is written in such a way as to deny
you the luxuries of either an 'abstain' option or a 'pending further
verification' category. One small mercy is tossed to you like a small bone
to a miserable dog: the magpie is not entirely sedentary; it shows a little
evidence of vagrancy at the northern edge of its range; the other two,
though....

The rest of the committee, and the birding community in each location, await
your decision on whether you will accept or reject their inclusions to the
State or Provincial Lists and your reasons for doing so.

As far as the Brambling is concerned, allow me to repeat Don Cecile's recent
remarks: there are known patterns of movements, timing, and distribution for
this and many other known-migrant rarities. What about a Brambling in summer
in Canada or the Lower 48, though? That would be a new record, but in
winter, they typically show up when Arctic jet-streams impel powerful
intrusions of Siberian arctic air into the Yukon and Alaska. They seem to
move south just ahead of or with the cold fronts as the edges of the frigid
air mass sweep south and west over the continent. There is a known pattern
and the sightings fit that pattern. So far.

Still, birds got wings: theoretically, they could appear anywhere. As Sherry
observes, they could, but observation shows that many of them don't or do
only under constrained conditions. Pattern and context are a help in
figuring out what they actually do as opposed to what they could do if they
felt like it. The fun is trying to figure all this stuff out!

Michael Price
Vancouver BC Canada
mprice at mindlink.net