Wed August 3, 1:09 PM ET

NEW YORK (AFP) - For ornithologists, it was the equivalent of finding Elvis, alive and well, singing his heart out in some isolated, rural shack.

Long-feared extinct, the ivory-billed woodpecker is now back in the building -- or in its case, a boggy woodland in Arkansas -- its return confirmed by audio recordings of the bird's distinctive call and tree rap.

The saga of the ivory-bill's rediscovery in the United States -- the last confirmed sighting was more than 60 years ago -- is one of amateur sleuthing, professional rancour and sightings that reduced at least one hardened bird-watcher to a sobbing wreck.

Scientific consensus on the bird's re-appearance was finally reached this week when a prominent trio of sceptical academics withdrew their challenge to news of the discovery after listening to the sound recordings.

"It was extraordinary, chilling ... just stunning," said Richard Prum an ornithologist at Yale University who was one of the leading doubters.

"Listening to that tape would elicit goosebumps from anybody who cares about this bird," Prum told AFP.

The tape, which featured the sound of two ivory-bills, headed off what was threatening to turn into a fully-fledged academic bust-up in the ornothological community.

The woodpecker's return was first trumpeted by a group of scientists in a paper they submitted to the journal Science in May, based on a series of sightings and analysis of a blurry, four-second video.

Prum and two colleagues -- Mark Robbins, an ornithologist at Kansas University, and Jeremy Jackson, a zoologist at Florida Gulf Coast University -- found the evidence insufficient and submitted their own highly critical paper to that effect to the Public Library of Science.

"The reviewers complemented us on our tone. The other authors did not," Prum acknowledged. "I think they wish it had been done in a private way, but this was science and we wanted to take a formal route."

After listening to the audio recording, the dissenters withdrew their challenge.

"We didn't withdraw because we thought we'd made any mistakes, but because there was new evidence that made our script moot," Prum said.

The search for the ivory-bill began in earnest after a one-time shiitake mushroom farmer, Gene Sparling, spotted a woodpecker with the right markings while kayaking in February through a swamp in eastern Arkansas.

"I cannot yet explain or fully comprehend why something so wonderful happened, certainly not why something so wonderful happened to me," Sparling, 49, told AFP in a telephone interview.

Although confident of what he had seen, Sparling was, at first, wary of publicising his discovery.

"I knew if I went and told someone I'd be laughed at," he said. "Even for me it was difficult to believe that a species that had been extinct my entire life wasn't extinct at all."

In the end he made a veiled reference to the sighting on a website, which was brought to the attention of Tim Gallagher, editor of the Cornell Lab of Ornithology's Living Bird magazine, and Bobby Harrison, an associate professor at Oakwood College in Alabama.

After interviewing Sparling, Gallagher and Harrison visited the swamp where, on February 27, they both saw what appeared to be an ivory-bill in flight.

After independently sketching what they had seen, the two men compared notes and concluded the bird was indeed the legendary woodpecker.

"When we finished our notes," Gallagher wrote in an account of the sighting, "Bobby sat down on a log, put his face in his hands and began to sob, saying, 'I saw an ivory-bill. I saw an ivory-bill'."

Gallagher said he was too choked with emotion to speak. "Just to think this bird made it into the 21st century gives me chills. It's like a funeral shroud has been pulled back, giving us a glimpse of a living bird, rising Lazarus-like from the grave."

The following month saw the formation of a full-scale search team, which documented further sightings and produced the brief video that formed the foundation of the Science article in May.

The rediscovery garnered national and international media attention, prompting concern that the woodpeckers habitat could be inundated with bird watchers.

"That's one of our biggest fears," said Morris, one of the converted dissenters.

"Could it become extinct because of people overrunning its place? We lost this bird once, we don't want to do it again," Morris said.

©AFP Media, 2005. All rights reserved.

Also see the Rediscovery of the Ivory-billed Woodpecker and the Piciformes section for more.