Campephilus p. principalis (Ivory-billed Woodpecker)

[another specialist]

admin said:

It might still be there. Although now they know its location it and they cannot find it, I also think it might not be surviving or maybe functionally extinct. On the other hand it might survive there and maybe even somewhere else. But I don't think it is a big population, only very few birds.

[another specialist]

melanie said:

By the way my sceptical question is based on an article by David Sibley in the current Issue of the Science Magazine.

Comment on "Ivory-billed Woodpecker (Campephilus principalis) Persists in Continental North America"
David A. Sibley,1* Louis R. Bevier,2 Michael A. Patten,3 Chris S. Elphick4
We reanalyzed video presented as confirmation that an ivory-billed woodpecker (Campephilus principalis) persists in Arkansas (Fitzpatrick et al., Reports, 3 June 2005, p. 1460). None of the features described as diagnostic of the ivory-billed woodpecker eliminate a normal pileated woodpecker (Dryocopus pileatus). Although we support efforts to find and protect ivory-billed woodpeckers, the video evidence does not demonstrate that the species persists in the United States.

1 Post Office Box 1031, Concord, MA 01742, USA.
2 Department of Biology, Colby College, Waterville, ME 04901, USA.
3 Oklahoma Biological Survey, Sutton Avian Research Center and Department of Zoology, University of Oklahoma, Norman, OK 73019, USA.
4 Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, U-43, Storrs, CT 06269, USA.


* To whom correspondence should be addressed. E-mail: [e-mail]

The ivory-billed woodpecker has received considerable attention following the April 2005 announcement of its rediscovery in the "Big Woods" region of Arkansas (1–3). The conclusion by Fitzpatrick et al. (1) that the species persists is based on several observations, sound recordings that resemble ivory-billed woodpecker calls and double raps, and a short video recording. The recent sight records (1, 4) were all very brief and most involved a single observer, matching the pattern of reported observations over the past few decades (5–8). Although such observations provide strong impetus for continued searching and habitat protection, they cannot be taken to confirm the species' presence because they do not provide independently verifiable evidence. Nor is the audio evidence reported to date considered definitive (9). Thus, confirmation that ivory-billed woodpeckers remain in the United States rests on demonstrating that the "crucial video of a large woodpecker" (1) cannot possibly be a pileated woodpecker.

Fitzpatrick et al. list five features to support their conclusion that the bird in the video is an ivory-billed woodpecker: (i) size, (ii) wing pattern at rest, (iii) wing pattern in flight, (iv) white plumage on dorsum, and (v) black-white-black pattern presumed to be a perched bird (1). Our analysis of the digital video and deinterlaced video frames (10) demonstrates that this conclusion rests on mistaken interpretations of the bird's posture, that several features visible in the video contradict identification as a typical ivory-billed woodpecker, and that other features support identification as a pileated woodpecker. The assessment that follows is keyed to the labeled frames in Fitzpatrick et al.'s supporting materials [fig. S3 in (1)].

Size and wing pattern at rest. Fitzpatrick et al. assume that the bird was positioned vertically on the trunk with its wings more or less folded in frames 33.3 and 50 (Fig. 1A). Our examination of specimens and photographs indicates that a typical ivory-billed woodpecker in that position would exhibit considerably less white and more black than is shown in these frames (Fig. 1). In our analysis [supporting online material (SOM) text], these frames show a bird that has already opened its wings in flight, exposing the underside of a fully spread right wing that is extended vertically (Fig. 1C). The observed pattern is that expected of a pileated woodpecker in this posture, with extensive white on the underwing coverts and bases of the flight feathers. Our estimate of the length of the white patch in the video better matches the extent of white on the ventral spread wing of a pileated woodpecker than that on the dorsal folded wing of a typical ivory-billed woodpecker (but see cautions in SOM). Movement of the tail away from the tree in these frames is also consistent with the hypothesis that the wings are fully spread (see SOM). With this interpretation of the bird's posture, it is impossible to determine the bird's size or wing pattern at rest.




Fig. 1. (A) Frame 33.3 from (1), in which it is proposed that the black and white object to the left of the tree trunk is an ivory-billed woodpecker positioned as illustrated in the inset sketch. (B) Photograph of a mounted ivory-billed woodpecker specimen, illustrating the limited extent of white and the large amount of black on the folded wing typical of that species (Western Foundation of Vertebrate Zoology) (image flipped horizontally and cropped using Photoshop). (C) The posture we propose for the bird in the video. [View Larger Version of this Image (49K GIF file)]




Wing pattern in flight. To support their conclusion that the bird in the video showed "entirely white secondary and innermost primary flight feathers" (1), Fitzpatrick et al. presented video frames (with interpretive sketches) in which white can be seen on both wings and two photographs of pileated woodpeckers for comparison (video frames and sketches reproduced in our Fig. 2). Those sketches and the comparison pictures of pileated woodpeckers, however, are incongruent with the bird's posture in the selected frames (SOM text), as shown by the entire sequence of frames (fig. S2). In our analysis of the bird's posture, the white on the wings can be accounted for by the ventral surface; in addition, due to blurring, the video frames probably show more white than was actually present on the bird (SOM text). Throughout the bird's flight, it is seen in a rear view. Extensive white is visible only on the downstroke, during which the leading edge of the wings angles down to propel the bird forward and the rear of the wings twist up. Consequently, during the downstroke the ventral surface of both wings should be visible (Fig. 2, E and F) and the dorsal surface largely hidden. Pileated and ivory-billed woodpeckers both show extensive white on the ventral surface of the wings, and the presence of white is not diagnostic. In contrast, during the quick upstroke when the dorsal surface of the wings is most likely to be visible, the wings appear mostly dark (e.g., frames 216.7 and 333.3) (fig. S2); the entirely white secondary feathers of an ivory-billed woodpecker should be obvious throughout the wingbeat cycle. The observed pattern of little white on the upstroke followed by a large flash of white on the downstroke is expected for a pileated woodpecker.




Fig. 2. (A) and (C) show video frames (apparently frames 700 and 1000, although this is not stated) and interpretive sketches from Fig. 2 in (1). (B) and (D) show alternative explanations of the bird's positions in these frames that better match its appearance and behavior in adjacent frames, i.e., the bird is flying more directly away from the camera (sketches by D. Sibley). In each case, the new interpretation shows that the white in both wings is likely to be from their ventral surface. (E) and (F) illustrate the manner in which a bird's wings twist in flight, such that the leading edges are lower than the trailing edges, rendering the ventral surface of both wings visible during the downstroke when viewed from behind. (E) shows a female mallard Anas platyrhynchos [photograph, courtesy of Ducks Unlimited, scanned from (11); cropped slightly using Photoshop]. (F) shows a pileated woodpecker taking flight

[another specialist]

melanie said:

Does ivory-bill exist, or not exist? That is the question
BY SANDY BAUERS
Knight Ridder Newspapers
PHILADELPHIA - Deep inside the Academy of Natural Sciences, Nate Rice turns a key and the doors of a hermetically sealed cabinet soundlessly swing open.

Carefully, he slides out a tray of birds, each on its back, legs tucked, neck outstretched.

They are ivory-billed woodpeckers, echoes of a time when their species proliferated in our Southern swamps. Now, their neighbors are the passenger pigeon, the Labrador duck, the Carolina parakeet - all extinct.

But if Cornell University's renowned Lab of Ornithology is right, scientists will have to change the status of the ivory-billed woodpecker. The "Lazarus bird," as some now call it, may not be extinct after all.

The announcement last April that the bird had been spotted - more than once - in the Big Woods of Arkansas could signal the greatest ornithological discovery of our time.

Or the most disappointing case of mistaken identity.

Meanwhile, it's the biggest ornithological debate going.

Were the birds spotted just common pileated woodpeckers? Last month in the journal Science, bird-guide author David Sibley couldn't rule that out.

Or were they really ivory-bills, large and stunning enough to earn the nickname "Lord God" bird, because of the common exclamation when people saw one? (Said to be the third-largest woodpecker in the world, they stand 18 to 20 inches with a wingspan up to 31 inches and a weight of 16 to 20 ounces.)

A now-famous four-second video shot in 2004 in Arkansas is as frustrating as it is tantalizing.

Its clearest image is someone's hand. Then, in the fuzzy distance, a brief flapping, a flash of white.

Doubters say there is better film of Bigfoot.

Researchers have dissected the video and several audio recordings, analyzing color patterns on the wings, calculating the speed of the wingbeats, comparing sound spectrographs.

Cornell has funded two seasons of intense searching in the Big Woods, chalking up more sightings. What they really want now are irrefutable photos.

And, please, not just one bird - what good is that? - but a few breeding pairs.

Birders are riveted.

On a recent Saturday, a Bucks County (Pa.) Audubon Society talk by Jim Fitzpatrick, a Minnesota nature center director who says he saw the bird, drew double the usual number of participants.

A recent week took author Tim Gallagher, editor of Cornell's Living Bird magazine, from New York to San Diego to Florida to Connecticut to speak about the bird. People "want to hear it from someone who saw the bird," he said. Gallagher was in the midst of researching his book, "The Grail Bird," when, he says, he saw one himself.

Several birders from across the country have joined the search in Arkansas, volunteering for two-week stints to wade through the muck, dodging poison ivy and cottonmouths, and not just because they think the science is important.

"I wanted to see it, pure and simple," said Art McMorris, a freelance ornithologist and retired neuroscientist.

Harry Armistead, a librarian and amateur ornithologist, was "electrified" at last year's announcements. He spent two weeks of his vacation this year to help search.

Neither may say whether he saw the bird; Cornell exacts a promise of secrecy until it makes its own announcements.

Whatever happens, Gallagher intends to go back, be part of it.

"Some people say, 'I'd love to see it just once in my life,'" he said of the ivory-bill. "I tell you, it's just not enough."

Once common in the cypress swamps of the South, ivory-bills declined because loggers clear-cut their habitat. By the 1890s, the bird's demise was hastened by the very people who should have cared most: naturalists. They wanted to collect specimens before it was too late.

One Academy specimen dates from 1894, when A.T. Wayne shot it near the Wacissa River, in Florida's Panhandle.

The last undisputed sighting was in 1944. Since then, others have claimed to have seen the bird - in Florida, in Louisiana, in Arkansas. But they were met with doubt, even ridicule.

Gallagher understands the skepticism; "it feels too good to be true." But he contends that scientists' unwillingness to believe - and investigate - may have hurt the bird's chances of having its habitat protected.

Farmers are now offering some fields, cleared decades ago in the soybean boom, for conservation. Since 1982, says Jay Harrod, of the Nature Conservancy in Little Rock, 50,000 acres of habitat have been reforested.

In March, the Audubon Society cast its lot with Cornell and listed the ivory-bill among America's 10 most-endangered birds.

Yet as much as the Academy's Rice would like to believe in the sightings, he's unconvinced.

"That's a life that was lost," he says wistfully, lightly brushing the feathers of a specimen with his fingers. But he also speaks of its "immortality" because of its use to science.

His hope is that, someday, someone will find a feather in the Arkansas swamp, and a DNA match with an Academy specimen will end the debate.

Until then, they keep looking.

---

For information about the woodpecker and the search for it, visit:

www.birds.cornell.edu/ivory or www.nature.org/ivorybill.

[another specialist]

ivoryking58 said:

I can remember when I was 4, (I'm sixteen), my uncle claimed to see one and took pictures. Three look clear, and it may indeed, be the bird itself. If anyone wants a copy I can most likely email it to you.

[another specialist]

noisi said:

ivoryking58 said:

If anyone wants a copy I can most likely email it to you.

Why dont You post these pictures here ?

[another specialist]

anotherspecialist said:

Noisi i've sent him a PM to email them to my email. When i receive them i'll post them up here for everyone to see

[another specialist]

melanie said:

As far as i know there were about 40 sightings between 1946 and 2004 in Florida, Louisiana, Arkansas and other possible areas and no one (!) has ever made a satisfying foto that confirms the existence of this bird.

[another specialist]

carlos said:

Yes, and also the short video recorded in Arkansas is accompanied by some (perhaps many) sightings from different people, some of them certainly truthful observers, some of them even this very year 2006.

But the problem is that at this species present status (presumably extinct) any record need something more than the standard (good descriptions, field notes, etc.) needed to prove a "normal" rara avis to any "Rarities Committee".

People is looking for an "irrefutable proof", that is a video recording, a photograph, a sound record, or (the most irrefutable of all proofs) an specimen, if found dead or injured.

And that is extremely difficult, a real lottery. Perhaps a good scrutiny and assessment of the most truthful claims of sightings of this elusive pecker can help to maintain the hope alive of the persistence of its survival.

My advise is just give time to allow chances of a good record to happen.

[another specialist]

melanie said:

Here is another thread: extinctanimals.proboards22.com/index.cgi?board=otherextinctbirds&action=display&thread=1144558182

Don't forget to merge before you delete the other thread.

I never forget to merge

Thread has been merged and deleted now.

[another specialist]

admin said:

I think we can indeed move this thread back to the extinct birds section for now. The reasons are mentioned by Another Specialist and Carlos.

Whether it is extinct or not, and whether it has or had been rediscovered.... I can say really what I think. I have still my doubts...

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Here news from the BBC:
Woodpecker's existence questioned
Last Updated: Friday, 16 March 2007, 19:39 GMT

Further doubt has been cast on the claim that a bird long-thought extinct is alive in North America.

Fleeting video footage of what many experts believed to be an ivory-billed woodpecker was captured in 2004 in an Arkansas swamp.

But since then, searches have failed to find any hard evidence for the bird.

Now, Aberdeen University's Dr Martin Collinson has told the journal BMC Biology that the video may simply show a pileated woodpecker in flight.

Dr Collinson has re-analysed the footage and says the bird in the pictures appears to have black trailing wing edges rather than the unique white features associated with the ivory-billed woodpecker (Campephilus principalis).

The videoed bird also appears to flap its wings at the rate a pileated woodpecker (Dryocopus pileatus) would - 8.6 times per second.

Format fooling

"A poor quality video of pileated woodpeckers can look like ivory-billed woodpeckers - and in that respect it can catch an observer out; and a mistake can be made. And in this case, I think a mistake has been made," Dr Collinson told BBC News.

The Aberdeen researcher also argues that the missing bird's large size and colourful plumage would surely have been seen by now in the many follow-up surveys.

"The ivory-billed woodpecker isn't some small brown bird that can only be identified by one in a thousand; it's an enormous black and white bird with a red head," argued Dr Collinson.

"OK, these swamps are pretty remote, but there are hundreds of people in there, right now, looking for the ivory-billed woodpecker. Eventually these birds would turn up."

But others still hold to the idea that the video did indeed show an ivory-billed woodpecker.

John Fitzpatrick, a director of Cornell University's Laboratory of Ornithology, said that different formats of the footage resulted in "comparing apples to oranges".

He told the Associated Press that Dr Collinson's evidence about similarities in the birds' colouring, wing patterns and flight patterns were skewed as a result.

Robot hunt

When the 2004 video was released, it stunned ornithologists worldwide, with some comparing the discovery to finding the dodo.

It ignited hope that other extinct birds might be clinging on to survival in isolated places.

The last confirmed sighting was in 1944.

Researchers hope robot bird-watchers may yet have the final say. Automated cameras have been set up in the Big Woods refuge of Arkansas to continue to spy for the elusive creature.

"I am happy to be proved wrong; a good photo would end this debate," said Dr Collinson.

"I would be delighted; I would love to see an ivory-billed woodpecker."

Source: news.bbc.co.uk/2/hi/science/nature/6458591.stm.

I have my doubts aswell another blurred video clip is simply not enough in my eyes to say it's rediscovered. If so then many of this blurred photos and clips of tasmanian wolves should be classed the same as a rediscovery.

[Melanie]

Jonesboro, AR -- "The last verified spotting was in 43 or 44 in Northeast Louisiana and since then there have been tantalizing possible glimpes," said Arkansas State University's Ken Levenstein.

Levenstein is working toward his Ph.D and is a self proclaimed "birder".

Those tantalizing possible glimpses from over 60 years ago and a more recent possible sighting in an east Arkansas swamp have since had the bird world a-flutter that maybe just maybe the ivory billed woodpecker does exist.

"Unfortunately, there's not been any evidence that has convinced everyone," said Levenstein.

In this Arkansas swamp lined with 800 year old trees nestled in the heart of the delta so much attention is focused.

"I do believe that was an ivory billed woodpecker. I don't know what happened to it, why it was there, or why it's not there now, but I do believe that certainly indicates there could be others," said Levenstein.

"If there's not, there's not, and it would be a tragedy," said Levenstein.

Some would argue a multi million dollar tragedy, but other researchers are convinced they spotted the elusive creature.

Now, tens of millions will be spent trying to determine if the ivory billed woodpecker really does exist.

"A lot of that money is going to preserve that land for your children, my children and grandchildren and for people who like to duck hunt, or birdwatch, and really everybody," said Levenstein.

Researchers and birders are now desperate to find some hard evidence to prove this multi million dollar tax payers' investment will be fruitful and a revered bird will finally be found......

"You need pictures, film, videos or even better you need to find a nest.....otherwise it's just hear say," said Levenstein.

[Bhagatí]

identify.whatbird.com/obj/830/_/Ivory-billed_Woodpecker.aspx

and

Campephilus principalis bairdii

www.flickr.com/photos/10321525@N07/1394649693/

Campephilus principalis principalis
not so extinct

www.flickr.com/photos/imdreaminggreen/252956254/

[Bhagatí]

www.visualsunlimited.com/checkauth.jsp?key=campephilus&type=and

www.visualsunlimited.com/frame_photo.jsp?imageid=303811



Ivory-Billed Woodpecker (Campephilus principalis), almost extinct, fewer then ten birds probably exist, Eastern Cuba (museum specimen)

probably Campephilus principalis bairdii

[another specialist]

have copied and pasted above image into Campephilus principalis bairdii thread

extinctanimals.proboards22.com/index.cgi?board=otherextinctbirds&action=display&thread=1130778968

[Deleted]

Hi !

... a very stupid question ...

I once found a pdf which was about the Imperial Woodpecker, the Ivory-billed Woodpecker and the Cuban Ivory-billed Woodpecker.

This pdf was about that all three can be seperated on the species level, that means the Ivory-billed Woodpeckers form North America and from Cuba are two distinct species.

The question: Did I found that pdf here in the forum or somewhere else

I think I suffer from the Alzheimer's disease ...

[Peter]

admin said:

Mid-Pleistocene divergence of Cuban and North American ivory-billed Woodpeckers

We used ancient DNA analysis of seven museum specimens of the endangered North American ivory-billed woodpecker (Campephilus principalis) and three specimens of the species from Cuba to document their degree of differentiation and their relationships to other Campephilus woodpeckers. Analysis of these mtDNA sequences reveals that the Cuban and North American ivory bills, along with the imperial woodpecker (Campephilus imperialis) of Mexico, are a monophyletic group and are roughly equidistant genetically, suggesting each lineage may be a separate species. Application of both internal and external rate calibrations indicates that the three lineages split more than onemillion years ago, in the Mid-Pleistocene. We thus can exclude the hypothesis that Native Americans introduced North American ivorybilled woodpeckers to Cuba. Our sequences of all three woodpeckers also provide an important DNA barcoding resource for identification of non-invasive samples or remains of these critically endangered and charismatic woodpeckers.

Download full-text pdf: www.oeb.harvard.edu/faculty/edwards/research/documents/BiologyLetters_Ivory-billed.pdf.

Here another link:
www.birds.cornell.edu/ivory/latest/woodpeckerDNA/document_view (DNA Reveals New Details About Enigmatic Ivory-bills).

Is this the pdf you forgot? ;D

[Deleted]

Yes it is, thank You ! ;D

[Peter]

You're welcome!
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DNA Reveals New Details About Enigmatic Ivory-bills

From the toes of old woodpecker specimens, researchers gain a tool for searching for the Ivory-billed Woodpecker in the present, as well as a glimpse of the elusive bird’s past.

By Pat Leonard and Miyoko Chu
September 2006

According to the books, there is only one “Lord God” bird: the Ivory-billed Woodpecker. For years, many feared that it was extinct, both in the swampy forests of the southern United States and in the mountains of Cuba, the only other place ivory-bills have ever been found.
Now scientists mining ancient DNA from the toes of old woodpecker specimens have come up with new genetic information that may shed light on the elusive birds’ present as well as their past. Authors of the study, published in Biology Letters, extracted new DNA sequences from museum specimens that may help pinpoint evidence of surviving ivory-bills, based on feathers or other material gathered in the field. The DNA study also revealed that ivory-bills in North America and Cuba diverged from one another genetically about a million years ago. Because of their genetic differences, the authors suggest, the ivory-bills should be considered two species instead of one.

Led by Robert Fleischer, head of the genetics program at the Smithsonian National Museum of Natural History, the researchers extracted DNA from specimens of Cuban and North American Ivory-billed Woodpeckers, some of which were collected as long as 145 years ago. Except for the Cuban woodpecker’s slightly smaller size, the birds are nearly identical: big black-and-white woodpeckers with huge bills, flowing crests, and white lightning bolts shooting up their necks. Because they look so much alike, the Cuban and North American ivory-bills were thought to be especially closely related to one another.
Despite outward appearances, the new study suggests that the similar-looking Cuban and North American Ivory-billed Woodpeckers are no more closely related to each other than they each are to the Imperial Woodpecker, a bigger and somewhat more distinctive species from the highlands of Mexico, whose DNA was also sequenced for the study.

Conservation implications
Many believe that the Imperial Woodpecker and the Cuban ivory-bill are extinct; there have been no confirmed sightings of Imperial Woodpeckers in more than a decade, and none of ivory-bills in Cuba since the 1980s. North American ivory-bills were also feared to be extinct until 2004, when searchers documented at least one in the Big Woods of eastern Arkansas.

“Before the rediscovery in Arkansas, the main hope for ivory-bill conservation was in Cuba,” said Martjan Lammertink, a research scientist at the Cornell Lab of Ornithology and a coauthor of the study. “Showing these two birds are genetically distinct, even though they look similar, may bring renewed interest in the Cuban ivory-bill.”
Irby Lovette, director of the Lab’s Evolutionary Biology Program, said that study also shows the importance of the three woodpeckers as a group within their genus, Campephilus. “It’s now clear that the two ivory-billed subspecies and the Imperial Woodpecker are each other’s closest relatives. If we lose all three, we’ve lost a unique and spectacular evolutionary group of woodpeckers,” he said.

Knowing the code
Except for fleeting glimpses of Ivory-billed Woodpeckers, several seconds of video footage, and intriguing sounds, ivory-bills have remained elusive since their reappearance in 2004. Searchers have relied on high-tech tools such as remote video and audio recording devices, as well as NASA’s Laser Vegetation Imaging Sensor to locate the best potential habitat. In one case, they even collected black feathers from a search area in Arkansas and sent them to the Cornell Lab of Ornithology for DNA analysis. The results showed that the feathers were shed from a Pileated Woodpecker, an abundant species at the search site.
The new sequences from old museum specimens give researchers even more comparison material to work with in the future. “We use the genetic sequences as a sort of bar code to compare DNA from material collected from the field—feathers or droppings, for example,” Fleischer said.

The Cuban ivory-bill: Baird’s bird?
Will field guides soon list two species of Ivory-billed Woodpeckers? Although the authors of the new study suggest that Cuban and North American ivory-bills should be considered separate species in their own right, the official decision rests with the American Ornithologists’ Union Committee on Classification and Nomenclature.
Lovette, a member of the committee, said decisions to split or lump species are usually based on multiple lines of evidence. “The new data are intriguing, but place these birds in the gray zone where some biologists would classify them as two species and others would retain them as just one,” he said. “These results will likely initiate an interesting debate on how we should classify these birds.”
If, at some point, the Cuban bird becomes officially recognized as its own species, the story of the woodpeckers’ shifting taxonomy will have come full circle. The Cuban Ivory-billed Woodpecker was named for an early Smithsonian Secretary, Spencer Baird: Campephilus principalis bairdii, in the subspecies nomenclature. But based on the work spearheaded by the Smithsonian, the species list might eventually read Campephilus bairdii, or Baird’s Ivory-billed Woodpecker. Until then, ornithologists will once again be involved in debate over the enduring enigma that is the ivory-bill.

Wandering Woodpeckers
Theories about how Ivory-billed Woodpeckers made it to Cuba have included the possibility that Native Americans transported the North American ivory-bill to that island as recently as 600 years ago. By showing that the Cuban population is genetically distinctive, the new study provides solid evidence that the woodpeckers were on the island long before people ever got there.
Martjan Lammertink, a researcher at the Cornell Lab of Ornithology, said the genetic data suggest a likely natural pathway of colonization: “From Central America, one group crossed during a low-water period from Yucatan (Mexico) to Cuba. Another group went to the Sierra Madre and became the Imperial Woodpecker, and the rest went farther north and became the North American Ivory-billed Woodpecker.”
Because conditions were harsher in the mountains, researchers hypothesize that the Imperial Woodpecker became bigger and heavier than the other two to withstand the cold.


The original paper and supporting material is provided below courtesy of The Royal Society.

Mid-Pleistocene divergence of Cuban and North American ivory-billed woodpeckers
Biology Letters, May 16, 2006, DOI: 10.1098/rsbl.2006.0490

Robert C. Fleischer, Jeremy J. Kirchman, John P. Dumbacher, Louis Bevier, Carla Dove, Nancy C. Rotzel, Scott V. Edwards, Martjan Lammertink, Kathleen J. Miglia, and William S. Moore.
Supplemental Material
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Source: www.birds.cornell.edu/ivory/latest/woodpeckerDNA/document_view

[another specialist]

news.mongabay.com/2007/0826-woodpecker.html

[another specialist]

Extinct and Endangered Birds

Top row (l to r): Hook-billed Kite, Ivory-billed Woodpecker, Passenger Pigeon, Carolina Parakeet. Bottom row (l to r): Bachman's Warbler, Red-cockaded Woodpecker, Kirtland's Warbler

www.hiltonpond.org/ThisWeek070508.html