.... That's birder talk (actually the bird banding code) for the Ivory-Billed Woodpecker, a bird that no birder has added to his or her checklist for lo these many decades.
We hesitate to even wade into the debate about whether the Ivory-Billed has been refound or, as has been feared for decades, is in fact extinct. As most of our readers will know, the debate has gotten increasingly heated, with charges, counter-charges, personal and scientific reputations at stake, etc, etc.
Well, here goes. Since it was first announced in Spring '05 that a team led by the Cornell Lab of Ornithology had "refound" the Ivory-Bill in Arkansas, there have been growing challenges to that claim. As A DC Birding Blog points out, there's a lot of coverage of the issue, both current and historical, in Birding magazine, the publication of the American Birding Association.
Now comes a study in the journal BMC Biology that purports to cast further doubt on the sightings. The article analyzes the brief video clip of a bird in flight that the Cornell-led team said was an Ivory-Billed. If we understand this correctly, one of the arguments in favor of it being an Ivory-Billed was the wingbeat frequency in the bird captured on videotape. The article in BMC Biology, by J. Martin Collinson, analyzed that videotape and videotapes of the similar (and common) Pileated Woodpecker during "escape flights." It argues that the bird on the videotape was most likely a Pileated.
Your call. If the IBWO is out there, somone will find it.