Robotic Cameras Join Search for Elusive Woodpecker
BERKELEY, Calif., Feb. 20, 2007 -- High-resolution robotic cameras have been installed in the bayous of eastern Arkansas, and researchers hope the devices will help definitively prove the existence of the ivory-billed woodpecker.
Developed by researchers from the University of California, Berkeley, and Texas A&M University, the high-resolution intelligent robotic video system installed in the Bayou DeView area of the Cache River National Wildlife Refuge in Arkansas is part of a major effort to locate the woodpecker, once thought extinct, in its historic habitat.
The ivory-billed woodpecker was believed to be extinct, but several recent possible sightings have prompted a massive search. (Image courtesy of the Audobon Society)
If the researchers obtain conclusive photographic evidence of the woodpecker, it will settle a debate that has become heated in recent years and fascinated millions of people around the world. In the meantime, the new robotic video system provides detailed video sequences of other birds, suggesting a new high-tech approach to conducting field biology work.
The robotic video system is part of a new project, called Collaborative Observatories for Natural Environments (CONE) and funded by the National Science Foundation, to develop automated systems that can observe and record detailed natural behavior in remote settings. Ken Goldberg, a UC Berkeley professor of industrial engineering and operations research, and of electrical engineering and computer sciences, and his former graduate student, Dezhen Song, now an assistant professor of computer science at Texas A&M, are co-principal investigators of the project.
"What Goldberg has now done is take this lab camera into the field," said Robert Full, professor of integrative biology and director of the Poly-PEDAL (Performance, Energetics, Dynamics, Animal Locomotion) Laboratory at UC Berkeley, who worked with Goldberg on the early stages of the system's development.
Goldberg and Song recently teamed with researchers from the Lab of Ornithology at Cornell University to help look for the ivory-billed woodpecker. The bird, standing 18 to 20 inches tall with a wingspan of 30 to 31 inches, was considered the largest woodpecker north of Mexico when it vanished more than six decades ago.
It had been feared extinct for decades until sightings in recent years revived hopes of the species' survival. However, most eyewitness observations of the woodpecker were made while the bird was flying through dense forests, making it difficult to obtain photographic evidence of the sightings. In 2004, biologists made national news headlines when they captured a few seconds of video of what appears to be an ivory-billed woodpecker. But those sightings also generated their share of controversy, with skeptics claiming that the fuzzy image in the video, taken by David Luneau, associate professor of electronics at the University of Arkansas at Little Rock, actually depicted a common look-alike bird, the pileated woodpecker.
Hopes that the ivory-billed woodpecker survived extinction were renewed last September along the Florida Panhandle when another team of scientists from Auburn and Windsor universities reported sightings and retrieved a number of audio recordings of the bird's distinctive double knock. Still, none of the evidence to date has provided the definitive proof of the bird's existence that skeptics demand.
"A single photographic frame would have to clearly show the unique markings of the ivory-billed woodpecker," said Goldberg. "Much better would be a high-resolution video clip that would also capture its unique wing and flight patterns."
The researchers note that simply pointing video cameras at the sky and recording is not practical, as the images would quickly fill up the computer's hard drive. The challenge, they said, is for the software to automatically recognize when animals are present. "Passive infrared (PIR) motion sensors are sometimes used in wildlife research," said Goldberg, who has pioneered networked teleoperation systems for more than a decade. "The problem is that PIR sensors look for heat and are not triggered by birds flying overhead. So we're developing a robotic system that analyzes high resolution video in real time."
The robotic camera system developed by researchers at UC Berkeley and Texas A&M University is installed in the Bayou DeView area of the Cache River National Wildlife Refuge in Arkansas. The system is part of a major effort to locate the famed ivory-billed woodpecker. (Photo courtesy of Dezhen Song, Texas A&M University)
In February 2006 the Cornell researchers took Goldberg and Song out to the Cache River National Wildlife Refuge to find potential locations for the cameras. Because no one knows exactly where the bird might appear, the cameras must cover a relatively wide swath of sky. They settled upon a power line that cuts through the bayou and provides a 50-ft-wide clearing unobstructed by trees.
"It's a natural bottleneck in the forest, and birds passing through that corridor are relatively easy to spot because they expose themselves," said Ron Rohrbaugh, project director at the Cornell Lab of Ornithology. "At this location, we should have the highest probability of capturing an image of the ivory-billed woodpecker."
The two cameras -- one pointing east and the other west -- are powered by a 69 kV transformer and are connected to a computer that processes the data. The researchers decided against solar and battery cells because they wouldn't provide a reliable enough power source. Waterproof gear helps protect the equipment from the elements and the occasional bird dropping.
The researchers created software that keeps video files only when potential "bird flight" movement is sensed. The software is based on new algorithms that can handle the unpredictable conditions of a natural environment, filtering out false readings from clouds, water reflections and falling leaves.
"The program knows, for instance, that the ivory-billed woodpecker flies 20 to 40 miles per hour, so anything outside that range is deleted," said Song, who worked with Ni Qin, a computer science PhD student at Texas A&M, on the software.
"The high-resolution camera we have shoots at 22 frames per second, with approximately 2 to 3 megapixels per frame," said Song. "That's a huge amount of data that must be managed."
Collecting the video data involves a decidedly low-tech approach: Luneau takes a boat out to the site every two weeks to change the disk. He does an initial screening of the images from the hard drive, and then sends the data to researchers at Cornell, Texas A&M and UC Berkeley.
The researchers are continuing to fine tune the system and algorithms while combing carefully through each new set of video that is collected. They also acknowledge the possibility that the cameras may never capture definitive footage of the woodpecker.
"I'm hopeful, but not overconfident," Goldberg said. "We're willing to run this camera for years, and we're prepared to accept it if we never see the bird. But if this persistent robot out on the bayou manages to capture verifiable high-resolution images of the legendary ivory-bill, it would be a major discovery for scientists, for conservationists and for more than 45 million American bird-watchers."
Goldberg presented initial samples from the video system on Saturday at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Francisco. For more information, visit: www.berkeley.edu
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