2012年5月23日

The Ivory-Billed Woodpecker

The large ivory-billed woodpecker once nested throughout the southeastern United States and thrived in great expanses of virgin woodland that covered much of the region before the Civil War. These tracts of swampland, nicknamed the “Big Woods,” surrounding Arkansas’s Cache River, are called bottomland hardwoods and contain many dead and dying trees. Bottomland hardwoods attract beetles and so become a source of beetle larvae, the ivory-bill’s favorite food. After the Civil War, the lumber industry cut down swaths of hardwoods for building homes, and by the 1940s the bottomland had shrunk. Few residents living nearby saw the woodpecker again. On March 11, 1967, the FWS added the ivorybilled woodpecker to the endangered species list, though most biologists felt it was already extinct.

In 2004 a current of excitement ran through the world of ornithology. A kayaker paddling the Cache River had spotted a bird he believed was an ivory-billed woodpecker. Soon afterward two others caught on film a brief glimpse of a bird having the woodpecker’s characteristic markings. The director of the Cornell Lab of Ornithology, John Fitzpatrick, told National Geographic, “Through the 20th century it’s been every birder’s fantasy to catch a glimpse of this bird, however remote the possibility. This really is the holy grail.” Recordings taken in the densest parts of the bottomlands gave evidence of the ivory-bill’s distinctive double rap-rap on tree trunks. Birdwatchers converged on the Cache River and nearby White River National Wildlife Refuge, the last remaining places believed to support the special bird. Frank Gill of New York’s Audubon Society remarked, “It is kind of like finding Elvis.” Since 2004 persistent volunteers have made no additional sightings, though the Cornell group and the Nature Conservancy have devoted 3,000 hours of in-person searches and movemen tcontrolled photography. Robotic sensors scan the woods for any and all movements, while the Automated Collaborative Observatory for Natural Environments (ACONE) searches the Arkansas skies on the lookout for birds of any type.

Did a species thought to be extinct somehow manage to recover and begin to repopulate the area? The last tentative sighting occurred in 2005, but ecologists have wisely gone on the offensive in preserving what is left of the woodpecker’s habitat. Mr. Fitzpatrick told the Boston Globe in 2008, “The decline of the ivory-billed is an unspeakable American tragedy. This country was unable to save even a single square meter of pristine bottomland habitat. It all went under the ax and chainsaw. We may have lost this iconic bird, but, by God, we owe the ivory-billed this sort of exhaustive, scientific search. . . . If they are there, we also owe them a recovery program.” The Nature Conservancy has worked jointly with the FWS to set aside thousands of acres of woodpecker habitat. “The successful history of conservation in the Big Woods of Arkansas,” said the Nature Conservancy’s Scott Simon, “is the result of great partnerships—federal and state agencies working with other organizations, local communities, hunters and landowners.” The emotional support from people like Fitzpatrick plus government support provide the best chance for saving critically endangered species.

In 2007 the FWS designed a recovery plan for the ivory-billed woodpecker, should it indeed still hide in the swamps. The agency focuses on the following three goals: verify the existence of the bird by sightings, recordings, or nest cavities in trees; protect or add to current habitat; and study all factors that would threaten a potential ivory-billed colony. In an encouraging example of positive thinking, the FWS has set a goal of 2075 for the year in which the ivory-billed woodpecker will be removed from the endangered species list, a step called delisting.

The scientific community’s and the public’s reaction to the ivory-billed woodpecker sighting attests to the current state of many species that were once abundant. The ivory-billed woodpecker experience—whether or not the bird still lives—has offered good examples of the quick reactions and sound planning needed to preserve disappearing species.

Source of Information : Green Technology Biodiversity

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