Unlike its more famous cartoon cousin Woody the Woodpecker, the
ivory-billed woodpecker is thought to be extinct, or so most experts
have believed for over half a century.
 Image to right: An artist's image of what an ivory-billed woodpecker looks like. Credit: George M. Sutton/Cornell Lab of Ornithology
But last month scientists from NASA and the University of Maryland,
College Park, Md., launched a project to identify possible areas where
the woodpecker might be living. Finding these habitat areas will guide
future searches for the bird and help determine if it is really extinct
or has survived an elusive existence.
The question of whether the species still exists started when a kayaker
reported spotting the woodpecker along Arkansas' Cache River in 2004.
That sighting spawned an intensive search for the species by wildlife
conservationists, bird watchers, field biologists and others.
In June a research aircraft flew over delta regions of the lower
Mississippi River to track possible areas of habitat suitable for the
ivory-billed woodpecker, one of the largest and most regal members of
the woodpecker family. The project is supported by the U.S. Fish and
Wildlife Service and the U.S. Geological Survey.
 Image to left:
An image produced from the airborne LVIS instrument shows a
three-dimensional view of tree tops and vegetation in the tropical
forest of La Selva, Costa Rica. The color indicates the amount of laser
energy reflected from trees and leaves back to a sensor onboard the
aircraft. Credit: John Weishampel, University of Central Florida.
Scientists from NASA’s Goddard Space Flight Center, Greenbelt, Md., and
the University of Maryland used NASA’s Laser Vegetation Imaging Sensor
(LVIS) onboard the aircraft. The instrument uses lasers that send
pulses of energy to the Earth's surface. Photons of light from the
lasers bounce off leaves, branches and the ground and reflect back to
the instrument. By analyzing these returned signals, scientists receive
a direct measurement of the height of the forest's leaf covered tree
tops, the ground level below and everything in between.
"LVIS is aiding this search effort far beyond what aircraft photos or
satellite images can provide in the way of just a two-dimensional
rendering of what's below," said Woody Turner, Program Scientist at
NASA Headquarters, Washington, D.C. "The laser technology gives us the
third dimension, enabling us to better assess the complex vegetation
structure the plane flies over." The flights are the latest step in an
effort spanning over two years to find absolute evidence that a bird
once thought extinct continues to survive.
"We're trying to understand the environment where these birds live or
used to live, using LVIS-plotted features like thickness of the ground
vegetation and tree-leaf density, in combination with other factors
like closeness to water and age of the forest, to determine where we
might find them," said Turner.
"Through numerous studies, we have shown the effectiveness of the data
generated by this sensor for many scientific uses, including carbon
removal, fire prediction, and habitat identification,” said LVIS
project researcher Ralph Dubayah, a professor in the University of
Maryland's Department of Geography. “Lidar technology like LVIS
measures the vertical structure of the trees and ground, setting it
apart from other remote-sensing systems that provide detailed
horizontal information that tells us little about whether a green patch
of forest is short or tall, for example. When identifying habitats, the
vertical structure of the vegetation is of paramount importance to many
species, including a bird like the ivory-bill.”
 Image to right:
The red border shows the forested area in the White River Wildlife
Reserve of Arkansas where researchers flew in June and July, 2006 to
identify a possible habitat for the ivory-billed woodpecker. Click image to enlarge. Credit: NASA
The reported sighting of the ivory-billed woodpecker inspired a
year-long search by more than 50 experts working together as part of
the Big Woods Conservation Partnership, led by the Cornell University’s
Cornell Laboratory of Ornithology and the Nature Conservancy.
Researchers have followed reported sightings across a huge swath of the
southeastern United States, including the Gulf Coast, Alabama, and
Florida.
In April 2005, that team published a report in the journal Science that
at least one male ivory-bill still survived. However, some scientists
have challenged whether it really was the ivory-billed woodpecker that
was spotted. The NASA-University of Maryland project is designed to
provide detailed habitat information that search teams will use
beginning this fall for expanded efforts to find new evidence about the
possible survival of the bird.
The project also has a broader application, according to NASA Goddard’s
Bryan Blair, principal investigator for the project. “This field
campaign is part of an effort to develop approaches that bring together
many types of remote-sensing data for monitoring wildlife habitat.”
The research team previously used NASA's LVIS to study wildlife
habitats in old-growth forests in the western United States and rain
forests abroad.
Related Links:
+ Earth Observatory Conservation Study
Gretchen Cook-Anderson
Goddard Space Flight Center |
