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The identity of the bird in the Luneau video has been challenged in previous publications (e.g., Sibley and Jackson (pdf)). Now we have another paper that concludes that the bird in the video is a pileated rather than an ivory-billed woodpecker. This paper, by J. Martin Collinson, compared the Luneau video to similar poor quality videos of pileated woodpeckers in similar flight angles. You can read the abstract or the full open-access article (pdf). (Note that the pdf file is provisional.)
The Collinson paper undermines two key claims advanced in the Science paper that announced the rediscovery. One is that the bird in the Luneau video beats its wings too quickly to be a pileated woodpecker. The second is that the plumage patterns visible on the bird's wings are consistent with an ivory-billed woodpecker, but not with a pileated.
The Luneau video shows a woodpecker beating its wings at a frequency of 8.6 beats per second over eight wingbeats. This matches the frequency from an archived sound recording of an ivory-billed woodpecker in flight. The original paper claimed that this is too fast for a pileated woodpecker. However, videos reported in the Collinson paper recorded initial escape flights with frequencies of 7.1, 6.7, 8.0, and 8.6 beats per second, suggesting that wingbeat frequency from the Luneau video does not rule out a pileated woodpecker.
While both ivory-billed and pileated woodpeckers have black and white wings, they differ significantly in plumage pattern. Ivory-billed woodpeckers have white on the trailing edges of the dorsal and ventral surfaces, plus on the ventral covert feathers. Pileated woodpeckers have white only on the dorsal and ventral coverts. In flight, pileated woodpeckers have a very black appearance. (See this illustration for plumage differences.) The argument for the Luneau bird being an ivory-billed woodpecker boils down to the appearance of large white surfaces on both the dorsal and ventral surfaces of the wing. These white areas seem to extend to the wing's trailing edge. The Collinson paper shows that, in a low-quality video such as the Luneau video, a pileated woodpecker can take on characteristics that are superficially similar to an ivory-billed woodpecker. Further, the new pileated woodpecker videos resemble the Luneau video in several important respects. (A comparison of frames from the Luneau video with flying pileated woodpeckers can be found on pp. 29-31 of the provisional pdf, or in a jpg image here.)
It appears that the bird in the Luneau video is not necessarily an ivory-billed woodpecker rather than a pileated. Removing the Luneau video leaves sight reports and audio recordings as the remaining evidence for the woodpecker's survival. Neither would likely be accepted as sufficient evidence by a state or national records committee; the sightings are generally of poor quality, even though most reporters seem reliable, and the audio recordings do not eliminate other species completely. As Collinson points out, the video analysis does not mean that ivory-billed woodpeckers are extinct, but it does remove a key piece of evidence for their persistence.
Related materials:
The paper has also been covered by Nuthatch, Rob, GrrlScientist, BirdCouple, Bill, and Birder's World. The CLO posted its own detailed video analysis.
Earlier this week, I write about some ivory-billed woodpecker articles in the latest issue of Birding. See also my previous posts about ivory-billed woodpeckers.
