[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

More on Pacific-Slope vocals

If you are tired of the controversy of Pacific-slope Flycatcher call,
you can Delete now! Otherwise, here is more material of interest posted
over Birding Frontiers.

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

At 10:24 AM 1/27/00 -0600, Mark Stackhouse wrote:
>I would like to echo the comments of Joe Morlan and Tom Crabtree on your
>"Western" Flycatcher. Yes, the MPN does sound like a "typical" PSFC, but
>does that really mean anything? For several years I've been convinced that
>PSFC should occur in Utah during migration, and was actively searching for
>one. I've largely abandoned that quest, since I've become convinced that it
>is impossible to positively identify (in the field) a PSFC away from the
>breeding grounds. I don't know if the same is true for COFC.


  Its great that this discussion has surfaced again, and even better now
that we are getting more input from birders in the 'trouble area' where
Cordillerans can sound like Pacific Slopes. I don't have Johnson's papers
and can't look this up, so I wonder if he did do playback experiments in
some of these trouble spots? Are there data from playback experiments from
the Warner mountains? I assume there must be. Someone needs to see what
occurred during playback experiments, and it may clear up the situation for
the NC people. The NC folks conducted playbacks of known identity birds
(Pacific Slope and Cordilleran) and only had their bird respond to Pacific
Slope. I think this is noteworthy and would not hesitate to consider the
bird a Pacific Slope based on this information. If the bird was a
Cordilleran, even one that sometimes makes a Pacific Slope type call, then
it should have responded to the Cordilleran call. If it was a presumed
intergrade, it presumably would have responded to both calls, or shows some
interest in the Cordilleran calls or perhaps it would not have responded at
all. The birds I hear annually in Alberta seem to be intergrades, possibly
with more Pacific Slope influence than Cordilleran. Their contact calls
vary, but are never distinctly two parted and are often intermediate. The
calls which sound most like Pacific Slope increase steadily, listen to the
crappy recording at:


Calls of Pacific Slopes don't tend to rise steadily, but hesitate half way
through. Thus, they are sinusoidal on a sonogram while the bird I have on
my website shows very little of this patter althought its there. The North
Carolina bird is clearly sinusoidal, and thus is a "classic" Pacific Slope
call. Again, someone needs to compare to the sonograms published in Johnson
and make sense of this.

Having said that, maybe we should be content to use the name which makes
the least number of assumptions - Western Flycatcher. Either way, its a
damn good bird for North Carolina!!!



Alvaro Jaramillo
Senior Biologist
San Francisco Bay Bird Observatory
P.O. Box 247
Alviso, CA 95002

Home of the California Fall Challenge!!


Birds of Chile and
New World Blackbirds at : http://www.sirius.com/~alvaro