December 13, 2005

On the Arkansas Search for Ivory-Billed Woodpecker

By Deborah Zabarenko

BAYOU de VIEW, Arkansas -- Among ancient cypress swamps, bird experts and wildlife officials searched on Tuesday for the elusive ivory-billed woodpecker, focusing on irregularly shaped holes in some of the biggest trees.

"These would be C holes," said Ron Rohrbaugh, an ornithologist at Cornell University who is one of the leading scientists in the search for the bird that was previously presumed extinct.

Rohrbaugh noted that possible ivory-billed woodpecker nesting cavities are classified A, B or C, with A the best.

"Here we look for A holes," he said. "An A hole in a swamp is a good thing, not a bad thing."

To track down the rare ivory bill -- jet black and bright white with a red crest on the male -- Rohrbaugh and a team of experts and volunteers are fanning out through parts of the Big Woods section of Arkansas.

The ivory-billed woodpecker was believed extinct for the last 60 years until a positive sighting in February 2004 in an Arkansas swamp. A subsequent sighting by two bird experts, as well as a brief video of the bird, led researchers to declare in April 2005 that the ivory bill had survived.

Until the public announcement, researchers and volunteer searchers operated covertly in some of the most remote parts of the U.S. heartland. This year, the search is highly publicized in hopes it will attract more support for the conservation groups working to reclaim the bird's watery habitat.


Looking for holes in trees is an important part of the search, especially since the holes where an ivory-billed woodpecker might nest can be easily confused with those of a pileated woodpecker. But Rohrbaugh explained that a pileated woodpecker's hole is almost perfectly round, while an ivory bill uses an irregularly scalloped oval hole that may be 5 inches across at its largest point.

An intensive six-month search for the ivory bill began in Arkansas in November, taking advantage of the winter-bare trees, which aid in observation.

In addition to professional staff and more than 100 volunteers who will rotate into the area for two-week searching stints, there are sophisticated electronic video, photo and audio devices used to stake out likely ivory-bill haunts.

Previously, reports of sightings of the big bird were dismissed by professional ornithologists.

Their skepticism was warranted because of the destruction of the big old trees over much of the American southeast that began after the U.S. Civil War. The ivory bill's large size, with a body perhaps 20 inches long means it needs large trees to nest in. It is known to scale the bark off old, dying and dead trees to get at the cigar-sized grubs that live there.

Good observers are essential to catching a glimpse of the camera-shy ivory bill. So far, some 20,000 hours of searching by dozens of trained observers have failed to spot the bird. But that is understandable, given each woodpecker's presumed 12-mile (20-km) foraging range. Experts do not know how many ivory-billed woodpeckers might exist in this area.

The total search area in Arkansas takes in 550,000 acres

of forest and swamp. Since last year, searchers have covered about 160 square km (62 square miles).