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Taking n April 25, 2004, at 3:42 pm central daylight time, in the Bayou de View area of Arkansas' Cache River National Wildlife Refuge, while riding in a canoe, researcher David Luneau videotaped a bird many believed to be ex- tinct: an ivory-billed woodpecker. Or, did he? Luneau, an associate professor at the University of Arkansas, along with scientists at the Cornell Lab of Ornithology, made their case in an article published in Science magazine, to much excitement. But, eventu- ally, some experts and academics disagreed, saying that the four seconds of videotape showed a blurry pileated woodpecker, not the rare, possibly extinct, ivorybill. at's when professor and computer graphics legend Donald Greenberg and several colleagues, notably graduate student Jeff Wang (now a character TD at PDI/DreamWorks), enter the picture, as does the Cornell Ornithol- ogy Lab. Because the two woodpeckers in question have black and white wings with opposite patterns, Greenberg and his group suggested that maybe they could animate an ivory-billed and a pileated woodpecker, simulate the camera in the videotape, and create sequences of images for each woodpecker that could be pattern-matched and compared to the video. is simple suggestion attracted the attention of Kim Bostwick, a research scientist in the Cornell Ornithology Lab, and set in motion a series of projects that continue today. Wang built an accurate 3D representation of the ivory- bill that has become a research vehicle for David Kaplan, another graduate student in computer graphics. Brendan Holt, a third CG grad student, col- laborated with Bostwick to develop a method for motion-capturing wild birds in free flight that she is now adapting for a field study of manakins. "ese are astonishing little birds found in Central and South America that sing with their wings," she explains. roughout the process, Bostwick, who uses high-speed video and detailed anatomy to study the functional morphology of birds, worked with the CG students, developing field methods and evaluating the model and the animation. "[e computer graphics students] traversed a very great dis- tance from beginning to end," Bostwick says. "In the first one or two weeks we started working together, they had us look at an animation they had put together. To most people, it would have looked good. But we saw birds with woodpecker feathers flying like vultures. From there, they developed a sophisticated model that incorporated all sorts of things about anatomy and how birds fly. And, they were asking questions most people don't ask orni- thologists, like how feathers work and what their motion is like, things we don't know. We have a lot to learn about how birds fly." Building the Bird e first step was to build the model. Soon, the simple idea of match- ing the patterns on the wings evolved into creating a model that precisely matched an ivorybill. "Once we started getting into the literature from the Flight January 2010 n n n n Scienceā€¢Engineering The ivory-billed woodpecker above is digital, created at Cornell University. By Barbara Robertson

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