Saturday, February 25, 2006

Ivory-billed Woodpecker Celebration 11

On Saturday afternoon, members of the Cornell team began to share information in the audience-packed banquet room. After a welcome by Project Director Ron Rohrbaugh, Project Scientist Martjan Lammertink spoke about why ivory-bills are so elusive.

The species' size places it in an elite group of large woodpeckers, those that weigh more than 400 grams, Lammertink said. The IBWO ranks as the second-largest woodpecker on Earth amidst Imperial Woodpecker, Great Slaty Woodpecker and Korean White-bellied Woodpecker. All four species occur in a narrow range of latitudes, and all are vulnerable to outside pressures on their habitat.

The species also share four distinctions:
* the need for very large areas in which to forage because of their foraging techniques
* "Big animals need big areas," Lammertink said.
* their temporary food sources (such as wood-boring beetle larvae in recently dead trees)
* their tendency to live in groups (prior to James Tanner's research, IBWOs lived in flocks as large as 12 birds)

Then Field Supervisor Elliott Swarthout took the microphone. He began on a light note by saying, "I am about to start my third spring here, and I have yet to see or hear the bird. So if you have any ideas, please let me know."

Swarthout described the two search goals:
* to find a nest or roost and "tie the bird to a physical location"
* to obtain better footage

So far, Bayou DeView within Dagmar Wildlife Management Area is the only spot with good sightings, and the team believes that the birds are nomadic and that the source population lives in White River National Wildlife Refuge, based on James Tanner's work. Swarthout said Bayou DeView receives consistent coverage by the 22 full-time searchers as well as the rotating 112 volunteers during the six-month season.

During the systematic search for cavities and bark scaling, searchers walk a grid to evaluate trees and rank any evidence, he said. Then a person or a remote, time-lapse or motion-sensitive camera monitors the tree.

The search also uses autonomous recording units for four weeks at a time, Swarthout said. The ARUs allow the team to obtain real-time data before using manpower, and they allow for follow-up on searcher observations.

In the coming months, the search will incorporate four ultralite plans in a 50-meter staged formation. The pilots will wear helmet cameras, and one ultralite with a fixed camera will film the landscape below. "We have some pretty high hopes for these guys," Swarthout said.

Then Rohrbaugh regained the microphone to discuss the question "Does an Ivory-billed Woodpecker make a sound if no one's there to hear it?" He said the only known recordings were made in 1935, and then he played the kent recordings from the Singer Tract in Louisiana.

With the ARUs, the search team can have "ears in the forest," Rohrbaugh said. The liability is that each of the 30 ARUs can record 500 to 900 hours per week, creating a project total of approximately 17,000 hours.

To deal with that, software searches the ARU hard drives for signatures similar to that of a kent or a double-knock, he said. After playing kent calls recorded in 1935 in the Singer Tract, he played possible kents recorded on Jan. 29, 2005 in the White River NWR. Then Rohrbaugh played them back to back, prompting applause from the audience because of the similarity.

At the end of his presentation, Rohrbaugh asked for audience questions. One woman asked about keeping hunters out of the search areas because gunshots scare away birds. Rohrbaugh said that's not going to happen because there's no need to do so. In addition, hunters have maintained this habitat for years, and they're the folks who raised money to pay for habitat conservation via the Duck Stamp.



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