Ivory-billed Woodpecker
2007 Schools Wikipedia Selection. Related subjects: Birds
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| Campephilus principalis (Linnaeus, 1758) |
The Ivory-billed Woodpecker (Campephilus principalis) is a very large and extremely rare or extinct member of the woodpecker family, Picidae. It is officially listed as an endangered species, but by the end of the 20th century had widely been considered extinct.
Reports of at least one male bird in Arkansas in 2004 and 2005 were reported in April 2005 by a team led by the Cornell Laboratory of Ornithology (Fitzpatrick et al., 2005). If confirmed, this would make the Ivory-billed Woodpecker a lazarus species, a species that is rediscovered alive after being considered extinct for some time. However, despite the highly publicized announcement of its rediscovery, skepticism about the reported sightings has been growing, with a number of prominent experts questioning the evidence.
In June 2006, a $10,000 reward was offered for information leading to the discovery of an Ivory-billed Woodpecker nest, roost or feeding site.
In late September 2006, a team of ornithologists from Auburn University and the University of Windsor published a paper detailing suggestive evidence for the existence of Ivory-billed Woodpeckers along the Choctawhatchee River in northwest Florida (Hill et al., 2006). To date, the group has been unable to obtain either photographic or material evidence of these birds, and their findings remain inconclusive. Some speculate that the focus should be on protection of habitat rather than further intrusive studies.
Description
The Ivory-billed Woodpecker is one of the largest woodpecker species in the world. The largest is the closely related Imperial Woodpecker (C. imperialis) of western Mexico, another rare species which is very likely to be extinct. The Ivory-billed measures from 48 to 53 cm (19 to 21 in) in length and 450 to 570 g (1.0 to 1.25 lb) in weight, with short legs and feet ending in large, curved claws.
The bird is shiny blue-black with extensive white markings on its neck and on both the upper and lower trailing edges of its wings. It has a pure white bill and displays a prominent top crest, red in the male and black in the female. These characteristics distinguish it from the darker-billed Pileated Woodpecker. Like all woodpeckers, it has a strong and straight chisel-like bill and a long, mobile, hard-tipped, barbed tongue. Its drum is a single or double rap, and its alarm call, a kent or hant, sounds like a toy trumpet repeated in a series or as a double note.
Habitat and diet
Ivory-billeds are known to prefer thick hardwood swamps and pine forests, with large amounts of dead and decaying trees. Prior to the American Civil War, much of the Southern United States was covered in vast tracts of primeval hardwood forests that were suitable as habitat for the bird. At that time, the Ivory-billed Woodpecker ranged from east Texas to North Carolina, and from southern Illinois to Florida and Cuba. After the Civil War, the timber industry deforested millions of acres in the South, leaving only sparse isolated tracts of suitable habitat.
The Ivory-billed Woodpecker feeds mainly on the larvae of wood-boring beetles, but also eats seeds, fruit, and other insects. The bird uses its enormous white bill to hammer, wedge, and peel the bark off dead trees to find the insects. Surprisingly, these birds need about 25 km² (10 square miles) per pair so they can find enough food to feed their young and themselves. Hence, they occur at low densities even in healthy populations. The more common Pileated Woodpecker may compete for food with this species.
Breeding biology
The Ivory-billed Woodpecker is thought to pair for life. Pairs are also known to travel together. These paired birds will mate every year between January and May. Before they have their young, they excavate a nest in a dead or partially dead tree about 8–15 m up from the ground. Usually two to five eggs are laid and incubated for 3 to 5 weeks. Both parents sit on the eggs and are involved in taking care of the chicks, with the male taking sole responsibility at night. They feed the chicks for months. About five weeks after the young are born, they learn to fly. Even after the young are able to fly, the parents will continue feeding them for another two months. The family will eventually split up in late fall or early winter.
Status
Heavy logging activity exacerbated by hunting by collectors decimated the population of Ivory-billed Woodpeckers in the late 1800s. It was generally considered extinct in the 1920s, when a pair turned up in Florida, only to be shot for specimens.
By 1938, an estimated 20 individuals remained in the wild, located in the old-growth forest called the Singer Tract in Louisiana, where logging rights were held by the Chicago Mill and Lumber Company. The company brushed aside pleas from four Southern governors and the National Audubon Society that the tract be publicly purchased and set aside as a reserve, and clearcut the forest. By 1944 the last known Ivory-billed Woodpecker, a female, was gone from the cut-over tract (Smithsonian p 98).
Reported sightings: 1940s to 1990s
The Ivory-billed Woodpecker was listed as an endangered species on March 11, 1967, though the only evidence of its existence at the time was a possible recording of its call made in East Texas. The last reported sighting of the Cuban subspecies (C. p. bairdii), after a long interval, was in 1987; it has not been seen since.
Two tantalizing photos were given to LSU museum director George Lowery in 1971 by a source who wished to remain anonymous but who came forward in 2005 as outdoorsman Fielding Lewis.
The photos, taken with a cheap Instamatic camera, show what appears to be a male Ivory-Billed perched on the trunks of two different trees in the Atchafalaya Basin of Louisiana. The bird's distinctive bill is not visible in either photo and the photos - taken from a distance - are very grainy. Lowery presented the photos at the 1971 annual meeting of the American Ornithologists Union. Skeptics dismissed the photos as frauds, believing that the bird seen is either a misidentifed Pileated, or - seeing that the bird is in roughly the same position in both photos - a mounted specimen.
There were numerous unconfirmed reports of the bird, but many ornithologists believed the species had been wiped out completely, and it was assessed as "extinct" by the International Union for Conservation of Nature and Natural Resources in 1994. This assessment was later altered to "critically endangered" on the grounds that the species could still be extant.
2002 Pearl River expedition
In 1999, there was an unconfirmed sighting of a pair of birds in the Pearl River region of southeast Louisiana by a forestry student, David Kulivan, which some experts considered very compelling. In a 2002 expedition in the forests, swamps, and bayous of the Pearl River Wildlife Management Area by LSU, biologists spent 30 days searching for the bird.
In the afternoon of January 27, 2002, after ten days, a rapping sound similar to the "double knock" made by the Ivory-billed Woodpecker was heard and recorded. The exact source of the sound was not found because of the swampy terrain, but signs of active woodpeckers were found (i.e., scaled bark and large tree cavities). The expedition was inconclusive, however, as it was determined that the recorded sounds were likely gunshot echoes rather than the distinctive double rap of the Ivory-billed Woodpecker.
Since 2002, most of the attention in the search for the Ivory-billed Woodpecker has turned away from the Pearl River region, although several unconfirmed sightings were reported there in February 2006, see video clips.
2004/2005 Arkansas reports
A group of seventeen authors headed by the Cornell Lab of Ornithology reported the discovery of at least one Ivory-billed Woodpecker, a male, in the Big Woods area of Arkansas in 2004 and 2005, publishing the report in the journal Science on April 28, 2005 (Fitzpatrick et al., 2005).
One of the authors, who was kayaking in the Cache River National Wildlife Refuge, Monroe County, Arkansas, on February 11, 2004, reported on a website the sighting of an unusually large red-crested woodpecker. This report led to more intensive searches there and in the White River National Wildlife Refuge, undertaken in deepest secrecy for fear of a stampede of bird-watchers, by experienced observers over the next fourteen months. About fifteen sightings occurred during the period (seven of which were considered compelling enough to mention in the scientific article), possibly all of the same bird. The secrecy permitted The Nature Conservancy and Cornell University to quietly buy up Ivory-billed habitat to add to the 120,000 acres (490 km²) of the Big Woods protected by the Conservancy.
A very large woodpecker was videotaped on April 25, 2004; its size, wing pattern at rest and in flight, and white plumage on its back between the wings were cited as evidence that the woodpecker sighted was an Ivory-billed Woodpecker. That same video included an earlier image of what was suggested to be such a bird perching on a Water Tupelo ( Nyssa aquatica).
The report also notes that drumming consistent with that of Ivory-billed Woodpecker had been heard in the region. It describes the potential for a thinly distributed population in the area, though no birds have been located away from the primary site. A current concern is that many bird enthusiasts will rush to the area in an attempt to catch a glimpse of this rare bird. Ornithologists and veteran birders tell of adult woodpeckers abandoning their nests and young out of alarm at the encroachments of overenthusiastic birdwatchers.
Debate
In June 2005, ornithologists at Yale University, the University of Kansas, and Florida Gulf Coast University submitted a scientific article skeptical of the initial reports of rediscovery. However, after reviewing new sound recordings from the White River of Arkansas supplied to them by the Cornell team that reported the rediscovery, they announced in August 2005 that they had concluded that the bird has indeed been rediscovered and withdrew their paper. Yale ornithologist Richard Prum stated:
"We were very skeptical of the first published reports, and thought that the previous data were not sufficient to support this startling conclusion. But the thrilling new sound recordings provide clear and convincing evidence that the Ivory-billed Woodpecker is not extinct.
In August 2005, despite the arguments for the existence of at least one Ivory-billed Woodpecker, questions about the evidence remained. Cornell could not say with absolute certainty that the sounds recorded in Arkansas were made by Ivory-bills.
Some skeptics, including Richard Prum, believe the video could have been of a Pileated Woodpecker.
In December 2005, Richard Prum's position was presented this way:
Prum, intrigued by some of the recordings taken in Arkansas' Big Woods, said the evidence thus far is refutable.
On page 13 of the American Birding Association publication "Winging It" (Nov/Dec 2005), it was announced:
The ABA Checklist Committee has not changed the status of the Ivory-billed Woodpecker from Code 6 (EXTINCT) to another level that would reflect a small surviving population. The Committee is waiting for unequivocal proof that the species still exists.
In a commentary published in The Auk in January 2006, Jerome Jackson expressed hus skepticism of the Ivory-bill evidence in no uncertain terms:
Prum, Robbins, Brett Benz, and I remain steadfast in our belief that the bird in the Luneau video is a normal Pileated Woodpecker. Others have independently come to the same conclusion, and publication of independent analyses may be forthcoming [...] For scientists to label sight reports and questionable photographs as 'proof' of such an extraordinary record is delving into 'faith-based' ornithology and doing a disservice to science." (Jackson, 2006a),
sparking off a side debate coming close to personal accusation (Fitzpatrick et al., 2006b,c; Jackson, 2006b).
In March of 2006, a research team headed by David A. Sibley of Concord, MA published findings in the journal Science, saying that the videotape was most likely of a Pileated woodpecker, with mistakes having been made in the interpretation of its posture. They conclude that it lacks certain features of an Ivory-billed Woodpecker, and has others consistent with the Pileated (Sibley at al., 2006) The original Cornell research team stood by their original findings in a response article in the same issue of Science, stating:
Claims that the bird in the Luneau video is a normal pileated woodpecker are based on misrepresentations of a pileated's underwing pattern, interpretation of video artifacts as plumage pattern, and inaccurate models of takeoff and flight behavior. These claims are contradicted by experimental data and fail to explain evidence in the Luneau video of white dorsal plumage, distinctive flight behaviour, and a perched woodpecker with white upper parts." (Fitzpatrick et al., 2006a)
In May of 2006, it was announced that a large search effort led by the Cornell team had been suspended for the season with only a handful of unconfirmed, fleeting sightings to report. Apparently conservation officers plan to allow the public back into areas of the Cache River National Wildlife Refuge that had been restricted upon the initial reported sightings. The search team reportedly plans to resume the search in autumn after the leaves fall, although at a somewhat smaller scale and possibly focusing on the White River region.
2005/2006 Florida reports
In September 2006, new claims that the Ivory-billed Woodpecker may not be extinct were released by a research group consisting of members from Auburn University in Alabama and the University of Windsor in Ontario. Dr. Geoff Hill of Auburn University and Dr. Daniel Mennill of the University of Windsor have revealed a collection of evidence that the birds may still exist in the cypress swamps of the Florida panhandle. Their evidence includes 14 sightings of the birds and 300 recordings of sounds that can be attributed to the Ivory-billed Woodpecker, but also includes tell-tale foraging signs and appropriately sized tree nest cavities (Hill et al., 2006). This evidence remains inconclusive as it excludes the photographic or DNA evidence that many experts cite as necessary before the presence of the species can be confirmed. While Dr. Hill and Dr. Mennill are themselves convinced of the bird's existence in Florida, they are quick to acknowledge that they have not yet conclusively proven the species' existence. The research team will undertake a more complete survey of the Choctawhatchee River in the coming winter season in hopes of obtaining photographic evidence of the bird's existence.
Tourism
In economically struggling east Arkansas, the speculation of a possible return of the Ivory-bill has served as a great source of economic exploitation, with tourist spending up 30%, primarily in and around the city of Brinkley, Arkansas. A woodpecker "festival", a woodpecker hairstyle (a sort of mohawk with red, white, and black dye), and an "Ivory-bill Burger" have been featured locally. The lack of confirmed proof of the bird's existence, and the extremely small chance of actually seeing the bird even if it does exist (especially since the exact locations of the reported sightings are still guarded), have prevented the explosion in tourism some locals had anticipated.
Brinkley, Arkansas, hosted "The Call of the Ivory-billed Woodpecker Celebration" in February 2006. The celebration included exhibits, birding tours, educational presentations, a vendor market, and more.
Other facts
The Ivory-billed Woodpecker is sometimes referred to as the Grail Bird or the Lord God Bird (while the Pileated Woodpecker is known as the Good God Bird). National Public Radio interviews concerning the rediscovery of the species were conducted with residents of Brinkley, Arkansas, and then shared with musician Sufjan Stevens who used the material to write a song titled "The Great God Bird". Arkansas has made license plates featuring a graphic of an Ivory-billed Woodpecker.