Washington, April 28 (Reuters): The discovery of a woodpecker long feared extinct threw the bird-watching world into euphoria today over its ability to survive, undetected, for six decades.

?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,? said Tim Gallagher, a Cornell University ornithologist who has seen an ivory-billed woodpecker.

In February 2004, Gallagher was with fellow birder Bobby Harrison in Arkansas when they spotted an ivory-bill. Harrison sat down and cried.

The last confirmed sighting had been of a female, in Louisiana, in 1944.

The two bird-watchers had received a tip from amateur naturalist Gene Sparling, who led them to the spot at the Cache River National Wildlife Refuge in eastern Arkansas, where he had seen a big, red-crested, bird flying toward him.

Sparling checked his field book when he got home and was shocked. Its black-and-white patches clearly identified it as an ivory-bill.

As he paddled Gallagher and Harrison, an associate professor at Oakwood College in Huntsville, Alabama, through the bayou, a large black-and-white woodpecker flew across the water.

?Ivory-bill!? the excited men called out in unison.

Theirs was not the first sighting.

In 2003, Mary Scott had stopped to stretch her legs when she spotted what she believed was ivory-billed woodpecker.

?I stood transfixed as I saw the bird land on a tree about 50 feet (15 metres) away. I had an unobstructed view. The sight was overwhelming,? Scott wrote.

The bird was huge, and hanging from the trunk of the tree, its wings folded on its back. There were two large white triangles on the wings.?

Scott decided not to make her sighting public, in the hope of protecting the rare and elusive creature.

Sparling, Gallagher and Harrison had a similar idea and helped set up a search team called the Big Woods Conservation Partnership. Private donors chipped in a million dollars for the clandestine effort.

In April 2004, David Luneau, an associate professor at the University of Arkansas at Little Rock, captured four seconds of video footage showing an ivory-bill flying off a tree trunk.

Analysis of the tape confirmed the bird's identity and was published in the journal Science on Thursday.