Joe,
According to Birds of Oregon, C. s. frontalis is the expected form along the
east slope of the Cascades, with some contact and intergradation with C. s.
paralia across a zone of contact in the southern Cascades (eastern Jackson Co
per Ralph Browning). Birds in the Ochoco, Blue and Wallowa Mtns. are assigned
to C. s. annectens. It is fairly typical for subspecies in those mountains to
be similar if not the same as the subspecies found in the northern Rockies.
According to BOGR, this form has the white rather than light blue feathering on
the forehead. In my experience, this is only typical of birds in the southern
Rockies. I don't recall noticing white feathering on birds anywhere in Oregon
and I've done a fair amount of birding in the Wallowas and Blues in recent
years. We were in Montana this summer and I can't remember seeing any white on
the foreheads of birds there either. I asked Shawneen if she remembered seeing
white on the foreheads of Oregon birds and she couldn't. I did some birding in
New Mexico this past summer and instantly noticed the white forehead feathering
on the Steller's Jays, as it is quite startling when you are used to the light
blue feathered birds. According the National Geo Guide, white feathering is
limited to birds in the central and southern Rockies, with more northerly birds
in the Rockies having light blue eyebrows. This was confirmed in my check of
Birds of North America Online (BNA). Browning is cited multiple times in that
account and I believe he consulted the Eds. of BOGR on taxonomic questions, so
it's hard to imagine that a mistake on this particular species would have
gotten by him.
In BNA Steller's Jays are divided into two groupings, a "Northern Group"
(essentially all of the U.S. form) and a "Southern Group" (comprised of Mexican
and Central American forms). They make no distinction between "Coastal" and
"Interior" forms in the U.S., other than to point out that birds found more
easterly tend to be paler bodied and show more head to mantle contrast.
We definitely need some clarification on how Marshall sorted subspecies into
Coastal and Interior groupings. I wonder how easy it is to sort these birds to
subspecies in the field. Sounds like it can be done, but may not be something
that we want to entrust the general eBirding public with.
Dave Irons
From: dmarc-noreply@xxxxxxxxxxxxx
Subject: [orebird] Which ssp. group to use for Steller's Jay east of Cascades?
Date: Fri, 4 Mar 2016 21:03:05 -0800
To: orebird@xxxxxxxxxxxxx
Does anyone know which subspecies group I should add to the filter for
northern Oregon east of the Cascade Crest into the Ochoco Mts.? The only
three choices are the interior, coastal, and Central American Groups.
Obviously it’s either Coastal or Interior group, but I’m not clear which it
is. Brian? Any guidance?
Joe Blowers
Account management and archives: www.freelists.org/list/orebird
Reviewers for Oregon Counties: http://tinyurl.com/n4k64ef
