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Pacific-slope Flycatcher nay-sayers



Folks:

Here is a set of comments from an expert of Empidonax out West.
Basically, some folks are saying that you can't be 100% sure of a
Pacific-slope based on its calls. Another person said the same thing,
and that where he is in AZ, they routinely let calling birds (P-s and
Cordilleran) alone, as Western-types. Several have said that becasue of
this mess, they disagreed with the AOU's splitting of these two forms
into species.

Hmmm -- how positive must one be to determine a P-s Flycatcher?  100%?
The bird at Jordan Lake clearly gave Pacific-slope calls, and responded
strongly to taped calls of P-s and little or less to Cordilleran, based
on what other have told me.

As I am on the NC Bird Records Committee, and Jeff Pippen and I
discovered the bird, I want to gather all the facts. I don't want a
"tainted" record, but it is starting to get tainted.

If the bird does not show up after this bout of 20-inch snow, we'll want
to comb the woods to look for a dead flycatcher as a specimen. That is a
remote chance of happening. I'm not even sure if specimen P-s can be
distinguished from Cordilleran. (Supposedly the songs are somewhat
different and are the 100% distinguishing character.)

Seems like, at some point, you have to take into account the law of
averages, the 95% or 99% rule, etc., in science. Unfortunately, some or
many folks want to invoke the 100% rule.

For now, I think it is best to call the bird at Jordan Lake a
Pacific-slope Flycatcher, without quotes. Maybe we'll need to put quotes
around the name. Even "Pacific-slope" Flycatcher, or
Pacific-slope/Cordilleran, or "Western" would be a first state record.

I sure would like "closure" on this record, but it looks as though that
will never happen. People should still check off Pacific-slope on their
checklists, but it looks as though "there is no way to be 100% that a
bird giving P-s calls is really a P-s" (according to some).
--
Harry E. LeGrand, Jr.
N.C. Natural Heritage Program
Division of Parks and Recreation
1615 MSC
Raleigh, NC 27699-1615

Office: (919) 715-8687
Home: (919) 832-3202
FAX: (919) 715-3085
e-mail: harry.legrand@ncmail.net
http://ils.unc.edu/parkproject/nhp/index.html



On Wed, 26 Jan 2000 10:55:30 -0500, Harry LeGrand
<Harry.LeGrand@NCMAIL.NET> wrote:

>all comments were in
>agreement that the recording is of P-s rather than Cordilleran.

How did they determine that?  Birds which are genetically Cordilleran
Flycatchers in the Warner Mountains of California routinely give the
sinusoidal call of Pacific-slope Flycatchers.  

I don't believe the identity of the bird can be determined from those
recordings.  I posted the following to ID Frontiers in 1997. Since
then, the situation does not seem to have changed.

>The recent thread on Cordilleran Flycatchers was originally
>started based on some observations by Jennifer Matkin and myself
>in the Warner Mountains in July.  Unfortunately we were away from
>access to BIRDWG01 during most of January, but have obtained all
>the messages from the archives.  These messages were quite
>helpful, but leave certain questions unanswered.  Also I have
>some personal correspondence on this subject from Ned Johnson and
>Jennifer has corresponded with Dick Cannings which sheds some
>light on the problem.
> 
>I was particularly interested in Louis Bevier's discovery of
>typical Cordilleran male position notes (MPN) on the east side of
>the Warners.  Our observations were on both sides of the Warners
>but primarily at the summit of Cedar Pass where we camped and
>spent considerable time studying a pair of Western Flycatchers.
>The male never gave the distinctly two-parted call which Bevier
>and Marantz reported from the east side. Furthermore Johnson (in
>litt) stated that birds in the Warners "rarely give" the
>distinctly two parted call.
> 
>The calls we heard were actually of three different types.  The
>most common MPN was a very slightly two-parted sharp "pseeet"
>(Johnson terms this "steeply rising). It also seemed to give the
>same call without the almost inaudible first part.  Thus a single
>high sharp "seeeet."  This bird also gave the lower, fuller,
>upslurred (Johnson calls it sinusoidal) call "suwheeet" typical
>of Pacific-slope Flycatcher.  The sinusoidal calls were given
>more frequently in the late afternoon and early morning.  Johnson
>(in litt) states that these vocalizations are all typical of
>Cordilleran Flycatcher in this region.  The implications of this
>have been touched upon, but I'm not sure they have been clearly
>articulated in prior discussion. Many Cordilleran Flycatchers
>from the western part of their breeding range do not give the
>distinctive two-parted call note of birds from further east.  In
>particular, migrants giving the typical sinusoidal call of
>Pacific-slope Flycatchers might actually be Cordilleran
>Flycatchers.  Such birds would almost certainly be misidentified
>by most birders using current field criteria.  In sum, migrants
>giving typical Cordilleran MPNs can be confidently identified as
>Cordilleran, but those giving typical Pacific-slope MPNs could be
>either one.
> 
>Johnson (in litt to Cannings) has stated that the best
>distinction is the SONG.  The song is three parted in both
>species as described by Chris Benesch.  However Johnson describes
>the distinction quite differently from Benesch. According to
>Johnson, it is the third part of the song that differs consistently
>between the species.  This part may consist of two or three
>syllables. One must consider only the two accented notes if the
>section is three parted.  On Pacific-slope the sequence of the
>two accented notes is low-high (sounds like "pittick" to me) and
>on Cordilleran it is high-low.  Notice that this approach pretty
>much eliminates the so-called "intermediate" song types.
> 
>I have not yet had a chance to visit the breeding grounds early
>enough in the season to test this difference in song and would
>like to learn what others think about it.  Does anybody have any
>recordings they can check?
> 
>One other question remains unresolved in my mind.  Although it is
>clear that Cordilleran may give Pacific-slope MPNs as well as the
>high thin "pseet" or "seet,"  I wonder if the reverse is true.
>Can Pacific-slope Flycatchers give a single steeply rising
>"pseet" or "seet" as a MPN.  I can give a partial answer.  I
>recall that Pacific-slope Flycatchers on Santa Cruz Island gave
>both calls.  This goes along with Johnson's view that the Island
>race is somewhat similar to Cordilleran.  But I simply cannot
>recall Pacific-slope Flycatchers elsewhere giving this call as a
>MPN.  I'm pretty sure I've heard it incorporated into some
>Pacific-slope songs though.
> 
>Any further comments would be most welcome.


-- 
Joseph Morlan, Pacifica, CA 94044: mailto:jmorlan@slip.net 
Birding Classes begin Feb 8 in SF: http://fog.ccsf.cc.ca.us/~jmorlan/
California Bird Records Committee: http://www.wfo-cbrc.org/cbrc/