At 06:22 PM 6/30/2010, Eugene and Nancy Hunn wrote:
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>Tweets,
>
>The weird warbler we reported last Sunday at
>Duvall was most likely a MacGillivray?s Warbler
>x Common Yellowthroat hybrid. Steve Mlodinow
>reports that this hybrid has been described
>previously and that some had the white throat we
>observed. Dennis Paulson thinks it could have
>been that the female was MacGillivrays, the male
>the Yellowthroat, which might help account for
>the otherwise puzzling white throat. The song
>(which I was not able to record) could
>conceivably have been described as intermediate
>between the songs of these two species, though
>if it learned its song from nearby songsters
>it?s a puzzle what species those might have
>been. If anyone is in the area and would like to
>try to relocate it, the GPS coordinates are N 47.73347, W 121.98959.
>
>Hal Opperman sent me a copy of a recent
>publication on the genetic evidence for
>hybridization between Pacific-slope and
>Cordilleran Flycatchers across southern BC and
>sw Alberta (which would apply as well to our
>northern tier of counties. (Andrew C. Rush,
>Richard J. Cannings and Darren E. Irwin.
>?Analysis of multilocus DNA reveals
>hybridization in a contact zone between
>Empidonax flycatchers,? J. Avian Biol. 40: 614-624, 2009.)

Tweeters,

For anyone who would like to delve into the
details of this paper, it is available for download at

http://www.appliedbioacoustics.com

Regards,
Arch McCallum
Eugene, OR

>Much of the article was devoted to technical
>methodological accounts of the laboratory
>procedures for comparing DNA, both mitochondrial
>and nuclear, which I take on faith.
>
>The results were instructive and support my view
>of the issue by-and-large. Compared with
>California reference samples for Pacific-slope
>Flycatchers and Cordilleran reference samples
>from Arizona, Colorado and South Dakota,
>Canadian samples from the Cascades and west were
>essentially Pacific-slope, but individuals from
>east of the Okanagan River valley to the Rocky
>Mountains of southeastern BC and southwestern
>Alberta were intermediate in nuclear DNA
>comparisons but close to Pacific-slope in their
>mitochondrial DNA (which, unlike nuclear DNA, is
>transmitted without genetic recombination
>through the maternal line). Genetic patterns
>varied clinally from west to east. They were
>cautious in their conclusions vis-?-vis the
>validity of the split but indicated that the two
>population may have been isolated for 350,000
>years before contact was reestablish in this zone.
>
>This pattern is quite comparable to what has
>been found with respect to the hybridization of
>Hermit and Townsend?s Warblers and is perhaps
>similar as well to our vexed ?Northwestern Crow?
>issue as well as the ?Olympic Gull.? In all
>these cases there is a broad zone of clinal
>variation between putatively ?pure? parental populations of two ?species.?
>
>Not reported here but described by Cannings and
>myself in a 1993 manuscript, the song features
>also vary clinally west to east from Okanogan
>County to Pend Oreille County, and on southward
>to the Palouse and Blue Mountains, where the
>populations are ?by decree? Cordilleran.
>
>So, the breeding Western Flycatchers in Ferry,
>Stevens, Pend Oreille, and northern Spokane
>counties should probably be simply listed as
>?Western Flycatchers.? Sorry if that messes up your county lists.
>
>Gene Hunn
>Lake Forest Park, WA
>enhunn323 at comcast.net
>
>_______________________________________________
>Tweeters mailing list
>Tweeters at u.washington.edu
>http://mailman2.u.washington.edu/mailman/listinfo/tweeters

D. Archibald McCallum, Ph.D.
Applied Bioacoustics
P. O. Box 51063
Eugene, OR 97405
phone 541 221 2112
www.appliedbioacoustics.com