Science via AP The ivory-billed woodpecker. Click photo for larger image.

The motor on his canoe rumbled quietly as birder Mike Lanzone glided through the Arkansas swamp, searching the shore through the cold rain. He thought he heard a woodpecker, but he wasn't positive it was the kind he sought.

His eyes scanned from his left to the front of the boat.

"That's when I caught a flash out of my right side," Mr. Lanzone said. "I saw the bird coming off a stump. It started flying very fast and straight and quartered away slightly. I immediately knew it was the bird."

That bird was an ivory-billed woodpecker, thought to be extinct for decades.

Almost a year ago, the search party led by the Cornell Lab of Ornithology announced in the journal Science that the bird had been rediscovered. In the paper, they documented seven sightings and analyzed four seconds of video footage of a woodpecker taking off from a tree trunk.

But last month, ornithologist David Sibley and other experts challenged the findings, writing in another article in Science that the Cornell team didn't have sufficient proof and contending that the indistinct video footage might well have captured a common pileated woodpecker.

"I am totally convinced it's there," Mr. Lanzone said. But he concurs that more evidence might be needed to convince everyone.

"It would be great to get that full-frame photograph to put on the front of a magazine," he said.

Mr. Lanzone, assistant field ornithology projects coordinator at the Powdermill Avian Research Center, a field station of the Carnegie Museum of Natural History in the Laurel Highlands, will give a talk reviewing the history of the bird and the debate about its existence at the museum on Saturday, as part of an Earth Day celebration. He plans to show video and play audio clips of the woodpecker.

		More Info Mike Lanzone will speak from 1 to 2 p.m. April 22 at the Earth Theater in the Carnegie Museum of Natural History. The lecture is free with museum admission. For information about Cornell's ivory-billed woodpecker project, go to www.birds.cornell.edu/ivory; to learn about Powdermill go to www.powdermill.org.

As a 6-year-old in Rochester, N.Y., Mr. Lanzone collected butterflies and memorized their scientific names. A couple of years later, he started watching birds. He and a friend built a lean-to on a large parcel of land that the friend's family owned.

When he found out that there was a well-known bird migration point a short drive from his home, he couldn't keep away. Thanks to an encouraging mom, he didn't have to.

The staff at Braddock Bay Observatory told the boy that he might be able to band birds with them when he was a teenager.

"Little did they know I'd be hanging out there every day," Mr. Lanzone said, laughing. "So I actually started banding birds at a very young age."

That training led to ornithology jobs as an adult. He's counted some of the 5 million to 7 million hawks that migrate in the fall from the United States to Veracruz, Mexico, worked with a kind of shore bird called a red knot in a telemetry project in New Jersey, studied spotted owls in Mexico.

"I am entirely self-taught," Mr. Lanzone said. He eventually took a job at Penn State and began working on an undergraduate degree, with the intent of continuing into a Ph.D. program.

He still had a few credits to earn for his bachelor's when he was asked to contribute to a six-volume photographic series about North American birds. Then, he was offered a job at Powdermill, where he's been for more than two years..

Mr. Lanzone was at a meeting when Kenneth Rosenberg, director of conservation science at the Cornell ornithology lab, asked if he'd be interested in a project in Arkansas. The professor refused to divulge details until they could speak privately.

But Mr. Lanzone's wife, who is also a birder, put the clues together and guessed that the project involved ivory-billed woodpeckers.

"It hadn't been made public," Dr. Rosenberg explained. "We were looking for top-notch birders and field people to go down and help, and I thought he was appropriate for that."

So in March 2005, Mr. Lanzone took to the bayous of eastern Arkansas with a flock of other skilled birders.

The search area focused on a portion of a 500,000-acre site, but as Dr. Rosenberg put it, even then "you're just a dot in the landscape."

Mr. Lanzone and his search partner suspect that they heard the ivory-billed woodpecker several times,. The bird's nasal call is likened to that of a toy trumpet; it's also called the "kent" call, because it sounds like the bird is repeating that word.

"I'm an exceptional birder by ear, and I'm very rarely stumped in North America by a bird sound," he said. "I had never heard anything like that before."

It was near that spot the next day that Mr. Lanzone glimpsed the elusive ivory-billed woodpecker. After videotaping the log that it might have rested on, and pulling from it a grub indented by the bird's efforts to extract it, he reported it to the field team leader. He then called his wife with the news.

"At that point it hit me, and I started to cry," he said. "I had tears for hours."

Mr. Lanzone's sighting and others didn't meet the strict criteria the scientists had set for inclusion in the research paper.

"He might be positive in his own mind and his own heart," Dr. Rosenberg said. "We're not saying he didn't see it."

More than 100 volunteers and 20 fulltime biologists were "out there all winter slogging around," he said. "Unfortunately, they haven't re-located this bird."

The Arkansas search will continue in the next field season, and others are taking it to other states, including Texas, South Carolina and Louisiana.