In 1979, Noel Snyder saw an aberrant Pileated in Florida that looked a lot like an Ivory-bill. Here's a snippet from page 30 of Snyder's book "The Carolina Parakeet, Glimpses of a Vanished Bird":
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Surely, mistakes in identification are sometimes made even by highly competent observers. Two examples from my own experience illustrate the risks clearly. One was a sighting of my own of an apparent Ivory-billed Woodpecker in central Florida in 1979. This was a bird that I flushed from a log in working through a hammock east of the Archbold Biological Station. The bird flew up to the vertical trunk of a pine only a few yards distant, and I could plainly see that it was a very large woodpecker with distinct large white secondary triangles on its folded wings, the most diagnostic field mark of the ivory-bill in distinguishing it from the somewhat similar Pileated Woodpecker.
Had the bird flown on immediately after I detected it, I would have been forever sure that I had seen a living Ivory-bill. But the bird remained perched on the pine trunk, giving me time to examine it more closely with binoculars. I soon determined that the white triangles on the bird's wings were in fact cream in color, not pure white, and in fact there were two black feathers intermixed with the cream-colored secondaries on the bird's left wing. Further, the bird lacked the huge white bill of an ivory-bill and instead had the much smaller black bill typical of a Pileated Woodpecker. I was almost surely looking at an aberrant Pileated with odd secondary feathers, not an ivory-bill, although optimists might suggest that it could have been a hybrid of the two species.
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I've been told that Pileated and Ivory-billed Woodpeckers are/were too distantly related to interbreed (they are in different genera).
On the back flap of the above book, it says that Noel Snyder is the author of four books on natural history subjects, and that he is a recipient of several national conservation awards.
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