Ivory-billed Woodpecker
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| Ivory-billed Woodpecker Conservation status: Critical | ||||||||||||||
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| Missing image Ivorybilledwoodpecker.jpg Ivory-billed Woodpecker | ||||||||||||||
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| Campephilus principalis (Linnaeus, 1758) |
The Ivory-billed Woodpecker (Campephilus principalis) is a member of the woodpecker family, Picidae. It is officially listed as an endangered species, and had until recently been considered extinct. Conclusive sightings of at least one male bird in Arkansas in 2004 and 2005 were reported in April 2005 (abstract (http://www.sciencemag.org/cgi/content/abstract/1114103)), which makes it a lazarus species. The reason for the species' decline is almost certainly loss of habitat.
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. It measures from 48–53 cm (19 to 21 in) in length and 450–570 g 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 the trailing edges of its wings. It can be identified by its pure white bill, which distinguishes it from the darker-billed Pileated Woodpecker, as well as by a prominent top crest, red in the male and black in the female. 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.
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Habitat and diet
Ivory-billeds are known to prefer old hardwood forests, with large amounts of dead trees and decaying wood, often in swampy ground. 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] (http://birds.cornell.edu/ivory/story11.htm). 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 three eggs are laid and incubated for 3–5 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. By 1938, only 20 or so individuals remained in the wild. The Ivory-billed Woodpecker was listed as an endangered species on March 11 1967.
In the U.S., the last confirmed sighting of the species had been during the 1940s. The last reported sighting of the Cuban subspecies (C. p. bairdii) was in 1987. 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] (http://www.iucnredlist.org/search/details.php?species=3712).
Pearl River expedition
In 1999, there was an unconfirmed sighting in the Pearl River region of southeast Louisiana by a forestry student. 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] (http://news.nationalgeographic.com/news/2002/02/0220_0220_newwoodpecker.html). 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] (http://birds.cornell.edu/publications/birdscope/summer2002/ivory_bill_absent.html).
Rediscovery
A group of seventeen authors headed by the Cornell University Ornithology Lab 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 by experienced observers over the next fourteen months. Seven sightings occurred during the period, possibly all of the same bird.
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 species. 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.
Other facts
This species used to be known by the popular name of "Lord God bird", for the exclamation that someone would make upon seeing a bird of its striking appearance and great size.
References
- The Ivory-billed Woodpecker (http://www.abirdshome.com/Audubon/VolIV/00426.html) 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 (http://audubon2.org/webapp/watchlist/viewSpecies.jsp?id=110), from the National Audubon Society.
- Winkler, H., D. A. Christie, and D. Nurney. Woodpeckers: A Guide to the Woodpeckers of the World. Houghton Mifflin Company, Boston, 1995. ISBN 0395720435.
- Fitzpatrick, John W. et al. (2005) "Ivory-Billed Woodpecker (Campephilus principalis) Persists in Continental North America (http://www.sciencemag.org/cgi/rapidpdf/1114103v1.pdf)". Science, published online (in PDF format) 28 April 2005; 10.1126/science.1114103.
- Once-thought Extinct Ivory-Billed Woodpecker Rediscovered in Arkansas (http://www.fws.gov/southeast/news/2005/r05-029.html), a press release from a website of the U.S. Fish and Wildlife Service.
- Hoose, Phillip M. (http://www.philliphoose.com/); The Race to Save the Lord God Bird, New York: Farrar, Straus, and Giroux, 2004. ISBN 0374361738 (children's book).
- Jackson, Jerome A. In Search of the Ivory-Billed Woodpecker. Smithsonian Institution Press, 2004 ISBN 1588341321.
- Gallagher, Tim The Grail Bird: Hot on the Trail of the Ivory-Billed Woodpecker. Houghton Mifflin, 2005 ISBN 0618456937.
External links
- 'Extinct' woodpecker found alive (http://news.bbc.co.uk/2/hi/science/nature/4493825.stm) from BBC News
- The Search for the Ivory-billed Woodpecker (http://www.museum.lsu.edu/~Remsen/IBW.html), from a Louisiana State University website
- The ivory-billed woodpecker has returned (http://www.nature.org/ivorybill/) with information on the Ivory-bill, its habitat, and the core search team, all from The Nature Conservancy (http://www.nature.org/)
- Online excerpt of The Race to Save the Lord God Bird (http://www.nature.org/magazine/fall2004/animals/), a book about the history of the Ivory-billed Woodpecker by author Phillip Hoose
- Live audio chat about the ivory-bill (http://www.nature.org/chat/) with Phillip Hoose, author of The Race to Save the Lord God Bird, on Tuesday, May 10, 2005 (archive to be posted after the chat)
- Website about the bird (http://birds.cornell.edu/ivory/) with video and sound files, from the Cornell Lab of Ornithology (CLO) website
- Radio Reports of the 2002 search (http://www.npr.org/programs/re/archivesdate/2002/march/), from National Public Radio, with streaming RealAudio
- U.S. Fish & Wildlife Service (http://news.fws.gov/NewsReleases/showNews.cfm?newsId=897957A5-1143-3066-401A20C9DFF1CE36) - April 28, 2005 news release regarding rediscovery of the Ivory-billed Woodpecker
- The Big Woods Conservation Partnership (http://www.ivorybill.org/), a group led by the CLO and The Nature Conservancy, formed in response to the bird's rediscovery
- Ivory-billed woodpecker photos (http://www.nature.org/pressroom/features/photos.html) from The Nature Conservancy, along with maps of ivory-bill's habitat (http://www.nature.org/pressroom/features/maps.html)
- The Ivory-billed Woodpecker is Rediscovered in Arkansas! (http://www.birdingamerica.com/Ivorybill/ivorybilledwoodpecker.htm), from the personal website of a birder in Arkansas
- Ivory-Billed Woodpecker (Campephilus principalis) Persists in Continental North America (http://www.sciencemag.org/cgi/rapidpdf/1114103v1.pdf) from Sciencexpress (Requires PDF file reader)
- Ivory-Billed Woodpecker habitat range in Georgia (http://narsal.ecology.uga.edu/ivoryga.htm) from the Natural Resources Spatial Analysis Laboratory's Georgia GAP Project
- 'Extinct' Woodpecker Found (http://www.cornellsun.com/vnews/display.v/ART/2005/04/29/4271dfcdb52d7?in_archive=1) from the Cornell University newspaper reporting on the discovery of the woodpecker.de:Elfenbeinspecht
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