Hi Tweets,

Denny Grandstrand writes:

>In his post to Tweeters this afternoon, Gene Hunn said that: " . . . while
>Couch's is much less likely, it should still be considered . . .". Last
>week Gene said there had never been a substantiated sighting of a Couch's
>Kingbird in the western U.S. If that is true, what are the chances of a
>Couch's showing up in the Pacific Northwest?

Nobody knows.

>Much, much, much less likely
>than a Tropical. Perhaps even too much less likely to be considered.

Nobody knows.

>Perhaps if we lived in Albuquerque we should be on the lookout for a
>Couch's. But we don't.

>There have been sightings in the northwest in the past few weeks that are
>being recorded as "Tropical/Couch's Kingbird" because of a very remote
>chance that the bird might have been a Couch's, especially since the bird
>was seen and not heard. If the chance of a Couch's Kingbird is so remote,
>why confuse the issue?

Because *nobody knows*. The short answer, Danny, is that we don't yet know
if it's a remote chance. There's opinion--I don't yet know enough about the
juv/post-breeding northward dispersal to have one BTW, there's surmise,
there's guesses, there's some data to suggest an inferential hypothesis,
there's sound and fury but the take-home truth is, we simply can't say for
sure because, just as simply, we don't know for sure.

Small numbers of dispersant Couch's Kingbirds may be intermingled with the
Tropical Kingbirds; they may not. Maybe you're right and the dispersal
northward along the West Coast is pure Tropical Kingbird and that for
anybody N of Albuquerque the ID is totally perfunctory and we don't need to
bother with the messy process of establishing the ID. But right now that
would be a lucky guess, Danny, 'cause you know as little as I do about it.
And the most important part of the reason we don't know is that we have
erected an a priori, tail-swallowing assumption that there's no Couch's in
that dispersal, therefore all the birds we see in it are, by the constituent
terms of that assumption, Tropicals. Case closed, dissenting opinion
irritating, inconvenient, irrelevant and wrong by the same a priori
definition. If it were only that easy. And we won't know until we stop
assuming that every bird we see is a Tropical. Maybe after another twenty
years' worth of fine-detail descriptions, recordings, high-quality videos,
we'll have a better, perhaps even definitive resolution of the situation,
but at present such an assumption and any pronouncements based on it are in
my opinion premature.

I'm simply suggesting that, like the birders of Nova Scotia, we keep an open
mind, and follow the usual procedure of assigning genus-only status to those
birds we can't ID conclusively. That we really dig into what's going on by
making sure that our field notes on these birds are as finely detailed as
possible, or if we can we get recordings and videos of the best quality
possible. We may even find some plumage feature or proportion, some postural
or behavioral thing, a habitat preference, something besides their calls
that will allow an easier visual definitive ID. For the record, I think it
*by far* the likeliest scenario that Tropical Kingbird is and will be the
most numerous, maybe the only tyrannid flycatcher we're gonna see in late
fall and winter, but that's just an opinion, a guess, and I won't dismiss
the possible presence of Couch's Kingbird until it's definitively
demonstrated that there are no, zip, bupkis, not one before or since *ever*,
Couch's in the northward Pacific Coast dispersal.

I'm really at a loss to know why we make an exception for this flycatcher
complex, given there's routine precedent. On the ocean, we have no
hesitation in calling a genus-only ID'ed bird a Xantus's/Craveri's-type
murrelet, a Cook's/Murphy's-type petrel, a Manx-type shearwater and so on
even though there may be no state or provincial records of either one or the
other instead of, for example, seeing a Cookilaria petrel and calling it a
Murphy's Petrel because that's the one we're *supposed* to see to the north,
or there's a 95% likelihood that if we do see a petrel in that genus, that's
the one it's likeliest to be.

It may be a puritanical personal eccentricity, but I am totally and
*categorically* opposed to the practice of ID'ing a rarity's species either
by assumption or by percentages or anything but species-diagnostic
plumage/song/call features. On any number of grounds ranging from the
procedural to the abstract. Call me a stubborn and odd-thinking purist if
you like, but if I can't tell, then I don't know. And if I don't know, that
bird gets a genus-only ID, no exceptions. No amount of statistical stuff
will convince me that it's nothing but a gussied-up guess otherwise.

Michael Price We aren't flying...we're falling with style!
Vancouver BC Canada -Buzz Lightyear, Toy Story
mprice at mindlink.net