NASA Joins Hunt For Woodpecker

Aug. 14, 2006 — Advanced three-dimensional imaging technology developed by NASA is being tapped to help find the ivory-billed woodpecker, a species whose extinction or existence hangs in the air.

Flown onboard a research aircraft this past spring and summer, the Laser Vegetation Imaging Sensor, or LVIS, was used to scan 1.2 million acres of dense forest in the delta region of eastern Arkansas, in the lower Mississippi River valley. This is where a sighting of the bird in 2004 reinvigorated an intensive search.

Unlike other remote sensing devices such as Landsat, the laser is able to pierce the dense canopy and collect data that is now being converted into maps. These maps will provide three-dimensional views of the forest structure.

"When identifying habitats, the vertical structure of the vegetation is of paramount importance to many species, including a bird like the ivory-bill," said project researcher Ralph Dubayah, a professor at the University of Maryland. Dubayah's team is collaborating with NASA Goddard's Bryan Blair, principal investigator for the laser instrument.

Since the sighting of the bird along Bayou de View in the Cache River National Wildlife Refuge in 2004, scientists have been combing the surrounding 500,000 acres of forest on foot. The effort is part of the Big Woods Conservation Partnership, led by  Cornell University's Laboratory of Ornithology and the Nature Conservancy.

Armed with video cameras and GPS devices, the scientists are not only hopeful that they will spot a living ivory-bill, but they are determined to locate holes in large, dead trees, where the birds are known to roost during the evening.

Upon finding such holes, the team members set up remote, time-lapse video cameras and acoustic sensors.

Trudging through hundreds of thousands acres of swamp and dense forest has been an enormous task for the 20 or so field biologists charged with the task.

Imaging technology will help researchers focus their efforts.

"This kind of remote sensing technology allows you to look into the forest from the air and narrow it down," said Martjan Lammertink, a search team leader and project scientist at Cornell University.

The instrument works by sending pulses of laser light to Earth's surface. The light bounces off leaves, branches and the ground and reflects back to the instrument, where the signal is collected and later analyzed.

Because the laser is able to penetrate depth at a high resolution — a 15-meter circle — scientists are able to glean important forest characteristics, such as tree height, trunk diameter, and the number of trunks per square meter.

Based on field research of the ivory-billed woodpecker conducted in the 1930s, before the bird went missing, scientists know what kind of trees the animal preferred.

Three-dimensional maps produced from the data allow search teams to pinpoint the most appropriate search locations within the vast swamps and forests of the Big Woods.

"There is still a pretty good chance that the bird persists in one or more of these areas," said Ken Rosenberg, director of Conservation Science at the Cornell Lab of Ornithology (www.birds.cornell.edu/ivory).

Search teams will begin a new hunt late this fall in an effort to settle the question once and for all.