Re: [CALBIRDS] "Cassiar" Dark-eyed Junco
- At 02:13 AM 2/25/2004 -0500, migratoriusfwlr@... wrote:
> On February 19th I had a junco up here at the Arcata Marsh project thatBefore the advent of listserves, the standard approach was to go to one's
> fit the description of the "Cassiar" "subspecies" which breeds in the
> northern Rocky Mountains in Canada. I was wondering if anybody could tell
> me of the status of the "Cassiar" junco in California? And I would also
> like to ask for the total number of records in California. I've never
> heard any mention of this subspecies in any of the literature or on any
> of the various california e-mail listserves.
bookshelf and pull down Grinnell and Miller's "The Distribution of the
Birds of California." This is perhaps the most basic and important
reference to the birds of the state and I can't imagine any birder being
without it. The relevant section in G&M reads:
Junco hyemalis cismontanus
Cassiar Slate-colored Junco
"Sparse but regular winter visitant from November to early
April. More of the Slate-colored Juncos wintering in the State belong to
this race than to J. h. hyemalis." Geographic range: "All sections of
State except coastal islands and Colorado Desert" [and that limitation, no
doubt, an artifact of coverage].
In Alden Miller's (1941) "Speciation in the Avian Genus Junco" there is
considerable detail about the appearance, distribution, and relationships
of this subspecies. Miller notes that it winters "with fair regularity in
>(I say "subspecies" due to much debate on the classification on this J.Miller again: "...it may be stated that cismontanus is a fairly uniform
>hyemalis cismontanus as an actual subspecies due to this subspecies being
>a well established product of Oregon and Slate-colored Junco hybridization
>which apparently goes against the subspecies concept. )
group of birds, doubtless of hybrid origin to begin with, which now
perpetuates itself independently of further hybridization of the parental
types J. oreganus and J. hyemalis. Cismontanus on the margins of its
breeding range breeds freely with J. h. hyemalis, which it most
resembles. In certain regions it does not interbreed freely with J.
oreganus, whereas at other locations hybridization is evidently frequent."
Since the breeding range of birds Miller classified as cismontanus is
rather limited, it's likely that many "cismontanus"-like birds in
California result from "Oregon" x "Slate-colored" hybridization occurring
away from Miller's mapped range of cismontanus.
A more detailed genetic/morphological study of juncos by George
Barrowclough is ongoing, and it is perhaps an understatement to say that
the results (many of which will be rather surprising) are eagerly anticipated.
Kimball L. Garrett
Ornithology Collections Manager
Natural History Museum of Los Angeles County
900 Exposition Blvd.
Los Angeles, CA 90007 USA