The reason I'm writing is that there is at least one article of interest just published. You may remember the Ivory-bill spread wing shown in a video tape interview of Joel Cracraft by Jim Gorman on the New York Times web site after Sibley's paper came out in Science. The article describing and illustrating that wing preparation has now been published in The Auk. The short article is available at BioOne online but requires a subscription (either to AOU or via an institution that has subscription to BioOne). The specimen is at the American Museum of Natural History.Below is Figure 4 from that article:
Fig. 4. Dorsal (left) and ventral (right) surfaces of left wing of male Ivory-billed Woodpecker (above) and
Pileated Woodpecker (below). Photograph by Craig Chesek (AMNH).
Posts
7 comments:
Very interesting picture. Are these wings really side-by-side? In which case the IBWO has smaller, more pointed wings than the PIWO. I wonder if this goes some way to explaining why one (usually) flaps faster than the other?
Interesting video, too. The Ivory-bill really isn't that much larger. It's easy to see how people can mistake where the white is on the wing if they're looking to see a particular feature. Having seen countless Pileateds, I wouldn't have realized how much white was on a Pileated wing before the controversy started.
Very interesting. Thanks for reposting it. The underwing of the IBWO certainly looks a bit different from the famous photo from the Singer tract. It seems to me that the IBWO wing is not fully extended as the PIWO's wing is. Look at the shape of the leading edge. The PIWO's curves outward while the IBWo's is curving to the inside (concave vs convex ?).
Dalcio
I've always been skeptical of the claim that IBWO, given its larger size and the paucity of evidence, has faster wingbeats than PIWO. But the obviously more pointed wing of IBWO suggests why it just might after all. I wonder how much of the difference in shape between the two taxa can be explained by preparation. Caution is warranted with a sample size of one. I'm hoping that somebody somewhere is conducting a comparative study of wingbeat rate, body size and wing shape in large woodpeckers.
I have to agree with Dalcio that the IBWO wing does not appear to be as fully extended as the PIWO wing, thus giving a false impression of shape.
Although we provide measurements of the wing in our article, we caution that shrinkage may have occurred due to Chapman's removal of all wing bones.The age of the specimen must also be taken into account, various amounts of shrinkage are expected over time.
We gently manipulated the wing open during our preparation as we did not want to damage it and this may have influenced the shape and size of the completed preparation.Pattern and color however remain accurate. The specimens are side by side in the photo, the central line was added later to clearly demarcate dorsal and ventral images.
Please see entire article in the April 2007 edition of "The Auk". Peter Capainolo
"shrinkage may have occurred"
We need to consult the expert on this topic, George Costanza
Post a Comment