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Re: P-SF logic



On Fri, 28 Jan 2000 Jcovington@aol.com wrote:
> 
> "The North Carolina bird is clearly sinusoidal, and thus is a "classic" 
> Pacific Slope call." (Alvaro Jamarillo, forwarded by Harry).

Of course, Al also said, in the same message, "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!!!"

I'm prone to agree with Al. If what we are concerned with is scientific 
accuracy, then the only way to be absolutely sure is to capture the bird 
and take measurements, maybe even blood and feather samples. If we cannot 
do this, then the scientific stance to take is that the bird is a Western 
Flycatcher, without specifying which daughter species it is.

From a lister's point of view, the only folks who need to worry are those 
who have seen Cordilleran but not Pacific-slope Flycatchers. There are no 
records for Western Flycatcher in NC, much less either of the daughter 
species, so this is a state bird for everyone, and a lifer for those who 
have seen neither of the daughter species. As long as you can make out 
the teardrop-shaped eye ring and yellow underside, that's enough to ID it 
as a Western Flycatcher, whether it calls or not. The first one ever for 
North Carolina!

The rest is up to the state committee. The probability is in favor of 
Pacific-Slope, particularly because the bird responded more strongly to 
that call than the Cordilleran call from a tape (assuming you trust the 
folks who made your tape...). Also, a post to the ID-frontiers listserv 
today by Colorado birder and bander Tony Leukering supports PCFL as a 
more likely eastward stray in fall migration than COFL (but note that he 
tells his field assistants to record banded birds at Westerns). And there 
is also the Pennsylvania bird, which was accepted by their state 
committee as Pacific-slope. But when is probability high enough to be 
accepted as certainty?

> 1. The speicies is separated from Cordilleran in the field uniquely by 
> call. 

Actually, if you reread Joe Morlan's commentary, the two species are 
separated primarily by *song*, NOT call. To quote Joe again "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." And our bird ain't singing...

> 2. The bird should be listed as P-SF. If the two species are not distinct 
> enough that they should be considered separate species, we will have to let 
> the authoriteis deal with that situation in the future. Until they do, what 
> we have is Pacific-Slope Flycatcher. 

For your own private lists, yes. If you report your list to the ABA for 
publication, then we cannot count this bird as Pacific-Slope unless the 
state committee accepts it as such. That's the rules of the game.

Good birding,

Josh



Joshua S. Rose
Duke University
Department of Zoology

jsr6@acpub.duke.edu
http://www.duke.edu/~jsr6/