It has been nearly a year since the tremendous hoopla surrounding the announcement of the rediscovery of the Ivory-Billed Woodpecker, a bird presumed extinct for 60 years. The evidence that the bird still existed in the swamps of Arkansas was presented in a paper in the prestigious journal Science, and consisted of some suggestive analyses of sound recordings, a small handful of sightings, and, most importantly, a short grainy video.
Many people, myself included, read this paper and looked at the evidence with discomfort. The title of the paper, “Ivory-billed Woodpecker persists in continental North America,” was unequivocal, whereas the evidence was certainly equivocal. The last year has seen this evidence debated among virtually everyone interested in birds, with blogs being created defending both sides (most notably Ivory-bill Skeptic and Ivory bills Live!”).
Last week, Science published the first peer-reviewed criticism of the evidence presented in the first paper; the lead author was well-known field guide author and artist David Sibley. A rebuttal by the original authors followed.
The details of the critique themselves — and believe me, they are painstakingly exhaustive — are secondary to the bottom line, which is that the original authors did not prove that the Ivory-billed Woodpecker really persists. Good, solid science requires the rejection of the the null hypothesis (in this case, that the bird in the video is not a common related species, the Pileated Woodpecker). Sibley and his co-authors presented a case that the bird in the video could have indeed been a Pileated Woodpecker.
In the Sibley paper, similar analytical tools were used to reach a different conclusion than in the original paper, akin to two researchers performing the same experiment and getting different results. Nor have the “results” presented in the first paper been replicated in two years of herculean search efforts in the Arkansas swamps by dedicated teams using the best technology.
In the world of science, a situation of this nature would generally be considered to be at the “back to the drawing board” stage. And I think that’s where the Ivory-billed Woodpecker is at. Still awaiting rediscovery.
The “rediscovery” of the Ivory-billed Woodpecker has many implications for science and conservation.