Nature article asks: But is it really alive?

Nature online has published an excellent article on the Ivory-bill controversy. In the article, two additional skeptics criticize the strength of Cornell's evidence--these skeptics are Gary Graves, the Smithsonian Institution's curator of birds, and ornithologist Michael Patten. According to the article, Richard Prum, Mark Robbins and Jerome Jackson now say that they withdrew their critical paper "too hastily".

Here's a key snippet:
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Even so, the three sceptics say that they withdrew their PLoS manuscript too hastily. They are getting support from other ornithologists, including Gary Graves, the Smithsonian Institution's curator of birds, who argues that the bird shown in the crucial video may be a pileated, not an ivory-billed, woodpecker.

And some authorities say that there is unpublished evidence that helps prove that the bird in the video is a pileated woodpecker. They are referring to a 1953 film of a flying imperial woodpecker (Campephilus imperialis), a species extinct in its home range of western Mexico. Some years ago, Lammertink secured a copy of the film, which had been taken by a birding enthusiast. It was among the evidence shown to ornithologist Michael Patten, research director at the University of Oklahoma's Sutton Avian Research Center in Bartlesville, when he visited Cornell in June.

Ornithologists generally agree that the imperial woodpecker is a sister bird to the ivory-billed, with many similar characteristics from coloration to the distinctive double-rap. But Patten was struck by the imperial's flight patterns. "As soon as I watched the film," he says, "I was absolutely certain they didn't have an ivory-billed woodpecker. The bird in the film flies utterly differently to the one in the Cornell video."

Fitzpatrick is not troubled by the film of the imperial woodpecker, arguing that it sheds little light on whether his video shows an ivory-billed. "They are like apples and oranges," he says of the two videos, because of different camera angles and stages of the birds' flights.

To the sceptics, the strongest evidence to support the theory that Elvis lives are the sound recordings. And although Prum and Robbins are impressed by them, Jackson, Graves and Patten are more cautious. The evidence is tantalizing, they say, but not conclusive. "The sound recordings don't validate the flimsy sightings records," says Patten.
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(I've added the bold font above.)