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."