[obol] Re: Black Butte Swamp thrush question and now Veery
- From: Steve Kornfeld <sbkornfeld@xxxxxxx>
- To: "llsdirons@xxxxxxx" <llsdirons@xxxxxxx>, Wayne Hoffman <whoffman@xxxxxxxx>
- Date: Sun, 8 Jun 2014 14:42:19 -0700
Back to the Black Swamp this morning. Numerous Swainson's thrush vocalizing.
Those seen (small fraction) were the Pacific or Russet-backed. We heard and
saw a nice pair of Veery. Annual in this area for a few years.
Olive-backed Swainson's breed in the Ochoco Range. For many years Veery breed
around the Ochoco ranger station. If Veery can hop on over to Black Butte,
perhaps Olive-backed Swainson's could also. I wonder what a careful census of
the Swainson's in this regions, (including Metolius Preserve, Suttle lake and
other nearby suitable areas) would reveal.
Steve Kornfeld
Bend
From: llsdirons@xxxxxxx
To: whoffman@xxxxxxxx
CC: sbkornfeld@xxxxxxx; obol@xxxxxxxxxxxxx; cobol@xxxxxxxxxxxxxxxxxxxxx
Subject: [obol] Re: Black Butte Swamp thrush question
Date: Wed, 4 Jun 2014 06:59:04 +0000
Like Wayne (see his comments below), I have yet to master the subtle
differences in the various White-breasted Nuthatch populations, but I've been
taking a lot of photos of White-breasteds over the past year or so.
The juxtaposition of Townsend's and Hermit Warbler breeding ranges that Wayne
describes–side by side east and west in Oregon and north and south up in the
Washington Cascades–is well illustrated if you compare the range maps for these
two species in the Peterson Reference Series "Warblers" guide by Jon Dunn and
Kimball Garrett. The Townsend's Warbler range map is on page 311 and the Hermit
Warbler range map appears on page 320.
I echo Wayne's encouragement to look closely at Swainson's Thrushes along the
east slope of the Cascades. It is quite possible that both types occur here and
that there is a contact zone. I've never seen an Olive-backed Swainson's Thrush
in the Oregon Cascades, but I can't say that I've paid much attention to the
appearance of the birds that I've encountered there (more often heard than
seen). Going forward, this is something that I will devote more attention to.
Dave Irons
Portland, OR
Wayne Hoffman wrote:
1. There are in fact serious rumblings about splitting Swainson's Thrushes. A
few years ago a graduate student in California (I think Berkeley but may have
misremembered) studied thrushes in the high Sierras, and found overlap or near
overlap without interbreeding. She wrote that they appeared to be acting as
separate species, but that "more study was needed." I am anticipating seeing
more on this in the near future. If we did find areas with both in Oregon
(e.g. east slope of the Cascades?) they might be very informative.
2. In Oregon, as Dave stated, Townsend's/Hermit Warblers as breeding birds act
as an east-west pair, with Townsends basically from the east side of the
Cascades in Central Oregon east through the Ochocos and Blue Mts. into the
northern Rockies. However, in Washington, it's a north-south phenomenon, with
Townsend's to the north of Hermits both in the Olympics and the Cascades. If I
remember correctly, Townsends breed right out to the coast in British Columbia,
so they have a much broader habitat tolerance.
3. I have not learned how to distinguish the kinds of White-breasted
Nuthatches. I have photos from Cabin Lake which I assumed are tenuissima.
When I see Steve Mlodinow's article I'll try to verify that.
Other related posts:
- » [obol] Re: Black Butte Swamp thrush question and now Veery - Steve Kornfeld
