A team of Cornell University scientists is in the process of searching for proof of the existence of the Ivory-billed Woodpecker, a bird long thought to be extinct. However, instead of using binoculars and cameras in their search, the scientists are using microphones and digital recorders.
“This is an experiment in conservation acoustics,” said John Fitzpatrick, director of the Cornell Laboratory of Ornithology.
Success will mean a clear recording of the ivory bill’s distinctive call, which is said to resemble a toy trumpet. Failure will mean more uncertainty, and less hope.
“[The odds of success] are low,” said Fitzpatrick. “We’ll either have a miraculous survival story or a sad endpoint.”
But the Ivory-billed Woodpecker has beat the odds before, even if only briefly.
The 20 inch tall bird with a wingspan as long as a man’s arm and a pterodactyl-esque head was first thought to have disappeared for good in the ’50s. It was rediscovered in the mid-’80s in Cuba before disappearing again, but credible sightings were also made in the United States in the late ’70s and again in 1999. It is this uncertainty as to their existence, coupled with their reclusive nature and inaccessible habitat — the swampy bottomlands and old-growth forests of the South — that makes bird-lovers cling to hope.
“It would be phenomenal [to have proof]. This was a bird that was a beautiful, majestic symbol of the southeast bottomland forest, and if it survived, it made it through the bottleneck of the mid-20th Century,” said Fitzpatrick.
That bottleneck was the logging of the whole of the southern old-growth forests at the turn of the (19th) Century. Because the ivory bill relies on the grubs and larvae that inhabit decaying trees for food, the elimination of this habitat was a crisis for the species.
“The tragedy is that we didn’t pay attention to their needs — not even in one spot,” said Fitzpatrick.
Now, however, the forests have grown back, and territory very similar to the ivory bills’ favorite habitats exists again. In the Pearl River Wildlife Management Area, deep in Louisiana, the conditions are just right.
So when a Louisiana State forestry graduate student named David Kulivan came forward in 1999 to say that he had seen these birds there while hunting — and at a distance of only 10 meters — scientists took notice. Kulivan, who had grown up on the river, provided details that convinced officials that his report was credible.
This led Zeiss Sports Optics, makers of the binoculars presumably carried by the team, to sponsor an expedition of six experienced birders to scour the Pearl River basin for 30 days this past January and February. At the end of the search, no definitive sighting had been made. But the scientists had found other signs of the birds’ presence — including trees with large areas of stripped bark — and had heard a series of double raps, a pattern unique to the ivory bill.
Thus, a second plan to find the birds was put into motion.
In 1935, an expedition headed by two Cornell scientists (including Arthur Allen, the founder of the Lab of Ornithology) made audio recordings of ivory bills. Their calls are highly distinctive, and a recording of the call would be just as good as a photograph of the bird in demonstrating their survival.
So with the previous recordings in hand, Cornell scientists conceived of the idea of placing recorders in the woods, turning them on, and walking away for a month and a half.
“We put 12 recording units in the forests of the Pearl River flood plain in January and they’ve recorded busily and faithfully until we took them out on St. Patrick’s Day,” said Fitzpatrick. “By putting an ear there that doesn’t look like a human we hope we’ll have a [better] chance for success.”
The devices being used are modified versions of ones used previously to record whales by the Bioacoustics Research Program at the Lab of Ornithology.
Kurt Fristrup, director of the Lab’s Bioacoustic Research Center, recently returned from Louisiana with the recordings.
“We recovered the instruments and they have recorded — and that’s all we know [so far].”
The scientists have close to 6,000 hours of ambient river sound of the Pearl River Wilderness, according to Fitzpatrick. Computers will be engaged continuously for the next one to three months, examining the thousands of hours of data for that one special sound.
Fristrup shares Fitzpatrick’s guarded optimism.
“Speaking as a skeptical scientist, I think the odds [of finding proof] are very slim. The fact that experienced birders walked around for a month and found nothing is discouraging,” he admits. “[But] these birds were hard to find even when they were common. I think it’s possible they do exist.”
According to Fristrup, the current fragmented state of the bird’s habitat may make finding them harder.
“Another possibility is that these birds are shy and good at avoiding people,” he added.
Even though the odds may be stacked against ivory bills, it’s certain a lot of people are pulling for them.
“It’s the largest woodpecker in North America, and the second largest in the world. It was magnificent physically. It was a wild looking thing and it stood for the forest primeval. Every birdwatcher that looks through a field guide longs for the idea that it exists somewhere,” said Fitzpatrick.
Archived article by Jennifer Frazer