[reccom] 3 records completed, 1 to 2nd round - Flycatcher thoughts

[Rick Fridell]

Hello Everyone,

I thought I'd send out my second round comments on the Pacific-slope
Flycatcher record to try and stimulate some discussion.


" Obviously this bird cannot be distinguished further than ‘western’
flycatcher.

I submitted this record for two reasons. The first is that as far as I know,
there are no other reports of western flycatcher or any other Empidonax
flycatcher in the winter in Utah. (I'm not sure we ever came to any
resolution, but I recall Mark suggested we review out of season
observations, and I concur that many of these types of observations are
intriguing and perhaps more significant, than say a vagrant Blackpoll
Warbler).

Secondly, I believe that it is an oversight that Pacific-slope Flycatcher is
not currently on the Utah list.

Even in hand, very few of these flycatchers are distinguishable, with nearly
all measurements showing extensive overlap. The only reliable way to
distinguish these species is genetic analysis (and allozyme analysis shows
these are distinct species that have been genetically separated for eons,
lack evidence of hybridization, and show assortative mating in areas of
overlapping breeding habitat). In addition, there is strong evidence that
the Channel Island Flycatcher (currently recognized by the AOU as a
subspecies of Pac-slope, E. d. insulicola) is likely a separate species.
Mitochondrial DNA analysis is going to provide insight into speciation and
genetic relationships of many currently recognized subspecies over the next
several years. And will very likely result in many, many additional splits
that will be nearly as difficult as western flycatchers (e.g. Red
Crossbills, Spotted Towhees, Common Ravens, Song Sparrows, Savannah
Sparrows, Fox Sparrows, Bushtits 

..and many more).

 I believe we should consider a process to evaluate these splits and their
corresponding probability of occurrence in Utah as they are accepted by the
AOU.  As I stated above, I believe it is an oversight that the Pacific-slope
Flycatcher is not on the Utah list.  I’m completely convinced it is a
regular migrant through southwest Utah. Nearly all western flycatchers that
I’ve observed in lowland locations, that have also vocalized, have given
both songs and calls consistent with Pacific-slope Flycatchers (including
the male’s two-note 'tee-seet' contact call). Also other factors previously
discussed (including, timing, habitat, lowland occurrence) suggest these are
Pac-slopes rather than Cordilleran Flycatchers. In addition, several other
species sharing the Pacific-slope’s breeding range and migration patterns
are regular or somewhat rare migrants through the southwest corner of the
state (e.g. Cassin’s Vireo, Townsend’s Warbler, Hermit Warbler, Red-breasted
Sapsucker, Vaux’s Swift). So there is no reason to expect this species does
not regularly move through southwest Utah.

With all that said, we face a bit of a quandary, and it’s likely to get much
worse over the next several years.  How do we empirically show a species
occurs in the state, if we cannot visually or audibly recognize it?  In the
case of Pacific-slope Flycatchers, there is no reason to suggest it doesn’t
occur, and in fact it is highly likely that it is a regular migrant through
the southwest corner of Utah.  However, it is visibly indistinguishable from
Cordilleran, shows overlap in songs and vocalizations, and even mist-netting
and measurements are unlikely to be definitive. So the only empirical
solution is genetic analysis, which is also prohibitive for a non-descript
uncommon to rare migrant through the state (yet rangewide a rather common
species).  I’d be very surprised if anyone has ever done genetic analysis of
Pacific-slope Flycatchers in say Nevada, however, it is currently on the
Nevada checklist and was added following the official split of Western
Flycatchers, based on the high probability of occurrence and migration
patterns of sympatric breeding species.

So, I’d be interested in hearing what you all think about a process to deal
with future splits of current subspecies. I believe this is really just the
beginning of a complex problem. "

I appreciate everyone’s time who made it all the way through this!

Thanks,

Rick

-----Original Message-----
From: reccom-bounces at utahbirds.org
[mailto:reccom-bounces at utahbirds.org]On Behalf Of Milt Moody
Sent: Monday, October 01, 2007 11:00 AM
To: Records Committee
Subject: [reccom] 3 records completed, 1 to 2nd round


Review page:
http://www.utahbirds.org/ReviewBirds/UnderReview.htm

Records 2007-22 for a Prothonotary Warbler, 2007-24 for a Reddish Egret
and 2007-25 for a Blue-headed Vireo were all accepted (7-0) in the
first round.

Record 2007-20 for a Pacific-slope Flycatcher has been sent to a second
round and is ready for your review.

Greetings from Dennis from Island Park, Idaho.

Milt


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