Ivory-billed Woodpecker

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Ivory-billed Woodpecker
Conservation status: Critical
Image:Ivorybilledwoodpecker.jpg
Ivory-billed Woodpecker
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Piciformes
Family:Picidae
Genus:Campephilus
Species: C. principalis
Binomial name
Campephilus principalis
(Linnaeus, 1758)

The Ivory-billed Woodpecker (Campephilus principalis) is a very large and extremely rare member of the woodpecker family, Picidae. It is officially listed as an endangered species, and until recently had widely been considered extinct. However, highly compelling sightings of at least one male bird in Arkansas in 2004 and 2005 were reported in April 2005 (abstract), and audio evidence suggesting the presence of the bird has also been collected. If its rediscovery is confirmed, this would make the Ivory-billed Woodpecker a lazarus species.

The Ivory-billed Woodpecker is the second-largest woodpecker in the world, slightly smaller than the closely related Imperial Woodpecker (C. imperialis) of western Mexico, another rare species which is very likely to be extinct. It 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.

The reason for the species' decline was primarily due to loss of habitat and also hunting by collectors. Even if the Ivory-billed Woodpecker is not extinct, most believe that only a handful could still be living.

Contents

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 [1]. 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 2 to 5 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 whole family will eventually split up in late fall or early winter.

Conservation status

Heavy logging activity and hunting by collectors decimated the population of Ivory-billed Woodpeckers in the late 1800s. It was given up for extinct in the 1920s, when a pair turned up in Florida, only to be shot for specimens. By 1938, only 20 or so 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, which brushed aside pleas from four Southern governors and the National Audubon Society that the tract be publicly purchased and set aside as a reserve. By 1944 the last known Ivory-billed Woodpecker, a female, was gone from the cut-over tract (Smithsonian p 98).

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. 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 [2].

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. In a 2002 expedition in the forests, swamps, and bayous of the Pearl River Wildlife Management Area by Louisiana State University, biologists spent 30 days searching for the bird [3]. In the afternoon of January 27, 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 [4].

Rediscovery

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.

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 believed 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. This is exactly what birders have been encouraged not to do by experts to avoid disturbing the birds. There are stories from when the species was more abundant of adult birds abandoning their nests and young simply because they were being watched.

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 arguements 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-billeds[5]. Some skeptics, including Richard Prum, believe the video could have been of a Pileated Woodpecker [6].

Other facts

The Ivory-billed Woodpecker is sometimes referred to as the Grail Bird or the Lord God Bird (a named shared with the Pileated Woodpecker). 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 "Lord God Bird". More information and the song can be found on the NPR website.

References

  • The Ivory-billed Woodpecker from the now public domain Birds of America by John James Audubon, hosted by a commercial website. ISBN 0810920611.
  • Watchlist entry for the Ivory-billed Woodpecker, from the National Audubon Society.
  • {{{Author|}}}{{|{{{3}}}}}}|show1| (1995)}}{{{{{Year|}}}}}}|show1|.}} {{|{{{3}}}}}}|show1|[{{{URL}}}}} Woodpeckers: A Guide to the Woodpeckers of the World{{|{{{3}}}}}}|show1|]}}{{|{{{3}}}}}}|show1|, {{{Pages}}}}}{{|{{{3}}}}}}|Show1|, Boston: Houghton Mifflin Company}}. {{{ID|}}}
  • Fitzpatrick JW, Lammertink M, Luneau MD Jr, Gallagher TW, Harrison BR, Sparling GM, Rosenberg KV, Rohrbaugh RW, Swarthout EC, Wrege PH, Swarthout SB, Dantzker MS, Charif RA, Barksdale TR, Remsen JV Jr, Simon SD, Zollner D (2005). Ivory-billed woodpecker (Campephilus principalis) persists in continental North America. Science 308 (5727): 1460-1462. PMID 15860589
  • U.S. Fish and Wildlife Service (April 28, 2005). Once-thought Extinct Ivory-Billed Woodpecker Rediscovered in Arkansas. Press Release
  • {{{Author|}}}{{|{{{3}}}}}}|show1| (2004)}}{{{{{Year|}}}}}}|show1|.}} {{|{{{3}}}}}}|show1|[{{{URL}}}}} The Race to Save the Lord God Bird{{|{{{3}}}}}}|show1|]}}{{|{{{3}}}}}}|show1|, {{{Pages}}}}}{{|{{{3}}}}}}|Show1|, New York: Farrar, Straus, and Giroux}}. {{{ID|}}} (children's book)
  • {{{Author|}}}{{|{{{3}}}}}}|show1| (2004)}}{{{{{Year|}}}}}}|show1|.}} {{|{{{3}}}}}}|show1|[{{{URL}}}}} In Search of the Ivory-Billed Woodpecker{{|{{{3}}}}}}|show1|]}}{{|{{{3}}}}}}|show1|, {{{Pages}}}}}{{|{{{3}}}}}}|Show1|, Smithsonian Institution Press}}. {{{ID|}}}
  • {{{Author|}}}{{|{{{3}}}}}}|show1| (2005)}}{{{{{Year|}}}}}}|show1|.}} {{|{{{3}}}}}}|show1|[{{{URL}}}}} The Grail Bird: Hot on the Trail of the Ivory-Billed Woodpecker{{|{{{3}}}}}}|show1|]}}{{|{{{3}}}}}}|show1|, {{{Pages}}}}}{{|{{{3}}}}}}|Show1|, Houghton Mifflin}}. {{{ID|}}}
  • Scott Weidensaul, "Ghost of a chance" Smithsonian Magazine August 2005 pp 97–102.

External links

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