Missing bird raises doubts among experts in the US – 05/21/2023 – Environment

If there is new hope, it is not clear. What is known for sure: The checkered history of the ivory-billed woodpecker, a majestic bird whose supposed extinction has been punctuated by a series of disputed rediscoveries, is still going strong.

The most recent twist is a peer-reviewed study published Thursday in the journal Ecology and Evolution that chronicles reports of woodpecker sightings, audio recordings, footage taken by cameras positioned on trails and videos taken by drones. The materials would have been collected over the past ten years in a swampy forest in Louisiana, the exact location of which has been omitted to protect the birds. The authors write that evidence suggests “the intermittent but repeated presence” of birds that look and behave like the ivory-billed woodpecker.

But are they?

“It’s the cumulative evidence from our search over several years that makes us very confident that this iconic species exists, that it still persists in Louisiana and likely elsewhere as well,” said Steven C. Latta, one of the study authors and director of conservation and field research at the National Aviary, a nonprofit bird zoo in Pittsburgh that leads a program that seeks out the species.

But Latta acknowledges that none of the material alone constitutes definitive proof. The study is carefully permeated with words like “possible” and “supposed”.

And that is precisely the problem. As one expert wrote in a previous case in which the woodpecker was reportedly sighted: “The body of evidence is only as strong as the strongest single evidence. Ten cups of weak coffee added together does not make a bottle of strong coffee.”

This time, two experts who were skeptical of previous sightings said they were still unconvinced.

“The problem is that the videos are very poor quality,” said Chris Elphick, a professor of conservation biology at the University of Connecticut and an ornithologist. Seen from afar or from certain angles, the Red-crowned Woodpecker (Driocopus pileatus) and the red-headed woodpecker (Melanerpes erythrocephalus) can look a lot like the ivory-billed woodpecker. The look can be confused due to the light. It’s easy to misinterpret audios.

“Frankly,” said Elphick, “I don’t think that changes much. I would very much like to be wrong.”

The importance of recent discoveries is great because the federal authorities responsible for natural protection proposed that the ivory-billed woodpecker be declared extinct. This would end the legal protection of the species. Last year, citing “major disagreements among experts regarding the status of the species,” the US Fish and Wildlife Service extended the deadline for announcing a final decision.

An agency spokeswoman, Christine Schuldheisz, said she does not comment on external studies but is working to reach a final decision, which is expected later this year.

According to the authors of the new study, removing federal protection would be detrimental to any remaining ivory-billed woodpeckers. But other scientists have noted that there is a high price to be paid to keep them on the endangered species list.

“It is critical to decide whether or not limited federal conservation resources should be spent chasing after this specter rather than saving other genuinely threatened habitats and species,” explained Richard O. Prum, professor of ornithology at Yale University.

Ivorybills began to decline sharply as Americans cleared their habitat, the ancient swamp forests of the southeastern US. Few of them still remained in the 1930s, but a scientific expedition discovered a nest of them in Louisiana, one of the largest areas of their habitat still remaining. The area had been leased for logging. Conservation groups tried to buy the rights, but the company refused to sell them. The last widely accepted sighting in the United States was in 1944, a lone female seen on her perch with the forest all around her cleared.

Since then, alleged sightings of the bird have sparked both joy and negative reactions. One, in 1967, was hailed on the front page of the New York Times. Twenty years later, another sighting – this time in Cuba, where it’s possible that a subspecies or similar species still lingers on – also made front-page news. In 2002, researchers in Louisiana thought they had picked up audio of the ivory-billed woodpecker’s distinctive double tap, but computer analysis determined that it was distant gunfire. An alleged warning in Arkansas in 2004 led to a scientific article in Science magazine and a surge in ornithological tourism, but this evidence has been heavily criticized.

For Elphick, who in addition to being a scientist has birdwatching as his hobby, one of the most revealing results is what so much effort has not yielded: a single clear photo.

“There are incredibly rare birds that live in the middle of the Amazon that people can get good, identifiable photos of,” he commented. “In the United States, people have spent hundreds of thousands of hours trying to locate and photograph ivory-billed woodpeckers. If there really is a population of them out there, I find it inconceivable that no one has yet gotten a good photo.”

But Latta, the study’s co-author, insisted he saw an ivorybill clearly with his own eyes. He was in the field in 2019 to set up audio recording units and reckons he must have spooked the bird. When she flew away, he could see her characteristic marks up close, without obstacles.

“I spent about three days without being able to sleep,” he said. “It was because I had this opportunity and felt this responsibility to make it clear to the rest of the world, or at least the conservation world, that this bird does indeed exist.”

Translated by Clara Allain