The search for the Ivory-billed woodpecker goes on. Wildlife Extra questions why?

15/10/2008 11:47:44

Ivory-billed woodpecker search 2007-08
The search teams covered lots of ground and tried new survey techniques. The U.S. Fish and Wildlife Service led the 2007-08 search effort with its partners from The Nature Conservancy, the Arkansas Game and Fish Commission, and the Cornell Lab of Ornithology. Searchers documented more possible sightings and possible ivory-bill double knocks heard, but the definitive photograph, like the bird itself, remained elusive.

"It's impossible to prove that a species is absent from any given place," said Ron Rohrbaugh, director of the Ivory-billed Woodpecker Research Project for the Cornell Lab of Ornithology. "The best that we can do is to search systematically, track our efforts, and statistically model the probability that we should have found what we are looking for. The problem is, with ivory-bills, the search effort required to make such predictions with a high level of confidence is nearly impossible to achieve."

For a species on the brink of extinction, it was imperative for the team to search as thoroughly as possible. During the 2007-08 season, they focused on eastern Arkansas and other areas of potentially suitable habitat in states where the ivory-bill has historically been found.

Six full time staff
Six full-time staff took to the field in Arkansas, the fourth field season spent in the eastern portion of the state. From December 4, 2007, until April 26, 2008, the team focused the bulk of their effort on unsearched or lightly-searched areas of the White River National Wildlife Refuge, though they also conducted a tree cavity inventory in the Wattensaw Wildlife Management Area to locate potential ivory-bill nesting sites. They also followed up on other potential sightings. The crew covered nearly 3,000 miles on foot and by boat, delving into some of the most remote areas of the White River NWR and camping for several days at a time. Our remote camera specialist Abe Borker reviewed approximately 2.5 million Reconyx camera images.

Five possible detections
The team documented five possible audio detections during the season. On January 27, for example, searchers heard three sets of double knocks near Kansas Lake in the White River NWR. "What's interesting about this is that they came in a series rather than the isolated double-knocks we've heard before," said Arkansas team leader Leighton Reid.

Helicopter surveys
The U.S. Fish and Wildlife Service arranged for helicopter surveys over the White River region in early February. "Trained photographers were able to find, focus, and shoot digital pictures of several species of woodpeckers that flushed near the aircraft," said Laurie Fenwood, the Ivory-billed Woodpecker coordinator for the U.S. Fish and Wildlife Service, Southeast Region. "However, a large percentage of birds did not flush at all, or fly where they were visible to observers. Testing this technique was important, even though its usefulness may be limited over such extensive forested areas."

Extra volunteers
Six volunteers joined the search for two weeks in March and helped maintain a presence in places like Bayou de View, Dagmar Wildlife Management Area, and several locations within the White River National Wildlife Refuge. In addition to the volunteers, businesses and hunting camps in the area were generous with information and in-kind support.

"We received a great deal of help from many people who made the search season safe, productive, and enjoyable," said Reid. "Special thanks go to Ken and Glenda at the St. Charles Community Store for their tolerance and generosity in giving us wireless Internet access so we could maintain our online search log and maintain communication with the Lab!"

Mobile Search Team
The four roving biologists on the mobile search team began their season in Texas, and moved on to Louisiana, Florida, Mississippi, and Alabama. They surveyed habitat in regions with exotic-sounding names such as Fakahatchee, Pascagoula, Tuscaloosa, and Atchafalaya, travelling many thousands of miles in the process. Various members of the team heard what seemed to be double knocks, but there were no definitive sightings.

A key mission for the mobile search team was locating promising habitat that could support ivory-bills. Team leader Nathan Banfield says, "I was impressed with the Mobile Delta of Alabama. It contained areas of large oaks and sweetgums with a lot of dead and dying wood. The Pascagoula River of Mississippi is also impressive. It has some of the nicest bottomland hardwood forest I've seen outside of Congaree National Park in South Carolina." The junction of the Chipola and Apalachicola Rivers in Florida showed promise along with areas in Big Cypress and Everglades National Parks in southern Florida.

Banfield concludes, "I still see a few places that could be home to an ivory-bill. In some areas, like Pascagoula, there is still a lot of ground to cover and most of the forest is amazing. I don't know if there is an Ivory-billed Woodpecker out there, but several areas show promise and give me hope."

2008 - 09 search much reduced
Fenwood says the U.S. Fish and Wildlife Service remains committed to locating any isolated populations of Ivory-billed Woodpeckers that may still exist, as well as to managing and protecting the unique habitat needed by the woodpecker and many other bottomland forest species. A number of conservation and science projects have evolved from ivory-bill search and recovery efforts which have helped refine management techniques for endangered species.

Discussions about the next field season are underway. Partners are presently organizing small strategic searches in areas that fall within the ivory-bill's historic range. The Cornell Lab of Ornithology will return to Arkansas if credible sightings are reported but at this point it appears unlikely that a full-time search team will be deployed. Preliminary plans call for assembling another mobile search team to visit more of the remote areas this year's crew found promising.

Last year of search
"We know there is suitable habitat within the Ivory-billed Woodpecker's historic range that we have not explored yet," said Rohrbaugh. "We're using habitat suitability models developed by the U.S. Fish and Wildlife Service and U.S. Forest Service to help establish strategies and priorities for searches in 2008-09. We believe with a third, and probably final year of mobile search team work, we will have visited all of the best potential places for ivory-bills to have survived."

To go to the Cornell Lab's webpages for the Ivory-billed Woodpecker Research Project, click www.birds.cornell.edu/ivory.