Sunday, October 30, 2005

-- The Imperial Woodpecker --

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In a prior "comment" Patrick Coin has referred folks to the following sites regarding the possible survival of the Imperial Woodpecker (the IBWO's Mexican cousin), and of course by googling "Imperial Woodpecker" you can discover still more:

http://birdforum.net/showthread.php?t=44627
http://www.birdersworld.com/brd/default.aspx?c=a&id=540

This all reminded me that when D. Kulivan claimed to spot 2 Ivory-bills in Pearl River, La. in April, 1999, I heard at least one individual speculate that maybe it was a case of mistaken identity and he actually saw Imperials -- apparently not realizing that this would be an even more incredible sighting (though Imperials had been observed more recently than Ivorybills, La. was totally outside their historical range).
Imperials are similar to Ivory-bills but significantly larger (by ~20%), and with a slightly different white pattern (possibly less dorsal and facial white, with possibly more white on the wings). But as one who doesn't like to summarily dismiss any possibility, consider this: the Ivory-bill is about 2-3 inches larger than a PIWO; I happen to think this is a significant amount and would be discernible in a quick glance by someone accustomed to seeing Pileateds, but others have argued that, at a distance, and with a brief look, that size differential could not be confidently registered. Yet, several of Cornell's sighters noted the sheer size of the bird they witnessed as being among the first fieldmarks that immediately jumped out at them, even with brief looks -- Is it possible that in the last half-century Imperials have moved slowly northward to escape the massive habitat destruction of their home range? Could remnants have dispersed into the American Southeast? -- no, I don't really believe that, but again I won't dismiss out-of-hand any possibility. Indeed, one of the things most troubling to me about the Luneau video is that to my eye the bird in question has always seemed TOO large and bearing TOO much wing-white even for an IBWO!

Addendum 11/7/05: here's yet another sighting of the Imperial reported to "Mexbirds" listserv from John Spencer in part as follows:

"Ron and Sarojam Makau are... avid bird watchers, who live near Cabo Pulmo, BCS. They are both professors at UC Riverside in the Biology Dept. They just got back from the Copper Canyon trip. They had some fantastic news … they are sure, absolutely sure, that the saw an Imperial Woodpecker (!) near Divisadero on the north rim of Copper Canyon. I questioned them closely, but they were sure, based on the description in Peterson...

They swear that they saw the female that has a very unusal reverse crest. They both are experienced birders and are biology professors at UC Riverside. They have birded all over the world and are really good birders. I believe their sighting.

They saw the bird about 30 ft up a pine tree, clinging to the trunk. They were about 50 to 60 feet away, with good light. They observed the bird for about 2 minutes, during that time the bird turned her head and the crest was seen at several angles, definitely matched the drawing in Peterson for the female. The bird flew off with slow heavy wingbeats. No sounds were heard. The sighting was about 0700 on the trail near the big hotel on the canyon rim.

I know that this is an unconfirmed and second-hand report, but I personally know the reporters and believe their sighting."

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1 comment:

Anonymous said...

That's so funny, your impression of the Lunneau video. To me it always seemed that the bird was too small--it seems to move rapidly and spryly through the woods, just like Pileateds I've seen. It does not seem to lumber at all on take-off and initial climb, as I would expect an Ivory-bill, a bird maybe 20% larger, and up to twice as heavy as a PIWO, to do. This is all very Rashomon-like--different people observe the same events and have different interpretations.

All the white on the wing--I'd wondered about that. The IBWO really has less white on the underside of the wing than the PIWO. Going through the web version of the video frame-by-frame, the large patches of white appear to me be visible on the underside of the wing, more consistent with a Pileated. In some frames, I believe I can see a black trailing edge to the wing, consistent with PIWO. I don't mean to belabor this, but you brought it up.

The whole problem with the video is that it is WAY out of focus and blurred due to the slow shutter speed--there is just not much you can say. Fine interpretations of what is seen on the video are very limited by the focus and blur, especially on things that are moving really fast, like the beating wings of a bird.

Hey, but the Imperial had no, or small, white stripes on the dorsum--maybe that is why nobody has seen them in Arkansas! (Just kidding--I think there is even less hope for the Imperial than for the Ivory-bill.)