The 2005-06 search for the ivory-billed woodpecker in Arkansas' 550,000-acre Big Woods has officially ended without any conclusive new evidence of the elusive bird's existence. But search crews remain optimistic about next season, experts from Cornell's Lab of Ornithology and others announced at a media teleconference May 18.
A panel of experts from the lab, the U.S. Fish and Wildlife Service (USFWS), Audubon Arkansas and elsewhere said there were four brief possible sightings since the search began last November, one by a search team volunteer and three by members of the public, but none of the fleeting glimpses of a large black and white bird in flight could be considered a definitive sighting. Within the ornithologists' ranking system, a definitive sighting requires clear view of at least two of the bird's diagnostic field marks. Each of the witnesses described and noted only one mark: white feathers on the wings characteristic of an ivory-billed woodpecker. A confirmed sighting, on the other hand, must include photographic or video evidence of the bird.
"Certainly we are somewhat disappointed, we probably wouldn't be truthful if we said we were not a little disappointed," said Ron Rohrbaugh, director of the Lab of Ornithology's Ivory-billed Woodpecker Research Project. The preparation and six-month search cost close to $1 million and included 20 full-time staff, 112 rotating volunteers, time-lapse cameras, automated recording units and supplies. Almost all the money was raised by private donations, with some material support and finances coming from the USFWS.
But, Rohrbaugh added, "we have had enough of these tantalizing sounds and possible encounters with birds, from the public as well as our own search team members, that we still have a lot of hope that there might be a pair -- especially in the White River area, where we've got more than 150,000 acres of forest." On a few occasions, members of the search team heard and recorded sounds similar to the ivory-billed woodpecker's distinctive "kent" calls and double knocks. The lab is currently analyzing these recordings.
In addition, in the White River area and the Bayou de View, a tributary to the Cache River where the one confirmed sighting took place, about 28 roost holes appeared to be the right size and shape for an ivory-billed woodpecker. Time-lapse cameras deployed on some cavities worked extremely well and recorded cavity use by other species of wildlife, including pileated woodpeckers, which have similar coloring and are often mistaken for the ivory-billed. The search team surveyed 33,000 acres during this year's search for a roost hole, making the total area searched around 72,000 acres, only about 13 percent of the total forest area in the Delta region of Arkansas.
Further, the Bayou de View, which had been under managed access and limited entry to only 76 permit-holding members of the public daily since the woodpecker was first sighted here in spring 2004, will now be reopened without restrictions, said Dennis Widener, Cache River National Wildlife Project Leader. The search team is confident that no ivory-billed woodpeckers reside in the Bayou de View at this time.
In November 2006, a new search will begin. Organizers plan to reduce the costs and efforts in Arkansas by relying mostly on highly trained and skilled volunteers from around the country as well as on automated recorders and time-lapse cameras trained on any promising feeding and nesting sites. The numbers of trained staff will be reduced, lowering costs to possibly as little as a third of those incurred in the latest search. There also are plans by USFWS to expand the search, possibly to Texas, South Carolina, Mississippi and other Southern states. Cornell plans to loan equipment and help train local teams to conduct searches in these new areas.
Along with partner scientists, lab experts are working with mathematical models to better understand how much effort would be required to conclude that the ivory-billed woodpecker no longer exists and the search should be stopped. All agree, that point of closure is far in the future.
"We have a number of more years of intense searching," said Ken Rosenberg, co-chair of the Lab of Ornithology's Recovery Team Biology Working Group.