The Ivory-billed Woodpecker's habitat should be protected despite the lack of definitive evidence of this species' existence, according to a new study published in Heliyon. Currently, bird conservation efforts rely on indisputable photographic evidence, which according to the new study could take many years to obtain, by which time it may be too late.

The Ivory-billed Woodpecker is an iconic species that is symbolic of the wilderness of North America. Threatened by habitat destruction and other factors, it has been declared extinct only to be rediscovered several times. In the absence of indisputable evidence, the discourse on the bird's existence has been dominated by opinion. After ten sightings during an eight-year search, Dr. Michael Collins of the Naval Research Laboratory in the US believes the Ivory-billed Woodpecker is alive -- but the bird needs our conservation efforts now, regardless of the proof, if it is to survive.

The birds live in vast swamp forests in North America -- Florida and Louisiana, in particular -- which are difficult and dangerous to access: with alligators, wild boars and venomous snakes, along with the risk of being accidentally shot in areas that are heavily hunted, most bird watchers will never visit the Ivory-billed Woodpecker's habitat. What's more, the thick vegetation means it is only possible to see for a few meters -- a challenge for searching areas of more than 100 square kilometers.

Ivory-billed Woodpeckers are highly elusive and wary of human contact, hiding away and keeping quiet at the first sign of threat. Using these behavioral and habitat factors, Dr. Collins has been able to approximately quantify the elusiveness of this bird, concluding that it would take significantly longer to photograph the Ivory-billed Woodpecker than similarly rare North American birds.

The analysis suggests we need to take a more pragmatic approach to documenting this species while it may still be possible to save it from extinction. In the past, sightings have led to intensive efforts to obtain a photo. But as well as being expensive, inefficient and ineffective, this approach could interfere with the birds' nesting attempts.

"There is no logical reason to require a particular form of evidence," said Dr. Collins. "When faced with an exceptional case, scientists often develop alternative approaches and make progress using different types of data."

In the paper, Dr. Collins presents three videos -- one of more than 20 minutes -- that show birds he believes to be the Ivory-billed Woodpecker as they have many characteristics consistent with the bird but no other species living north of Mexico. The bird's remarkable swooping flights, rapid wingbeats, and an audible double-knock are captured on film, consistent with reports from the 1940s and earlier. He observed the Ivory-billed Woodpecker ten times in 1500 hours of searching between November 2005 and June 2013.

"Having observed these birds is one of the two most deeply meaningful experiences of my life. When I was 11 years old, I stood in my front yard in Tampa, Florida, and watched Apollo 11 blasting off into space on the way to the first manned landing on the Moon. I feel very privileged to have been a direct eyewitness to a symbol of the vanishing wilderness of our world as well as one of the great achievements of humankind. My hope is that we will continue making progress and doing great things while at the same time preserving our natural world."