San Francisco ? In a bid to learn whether the ivory-billed woodpecker is extinct or merely very rarely seen, a team of scientists has built and deployed a robot video camera that switches on whenever a fast-moving, birdlike object crosses its field of vision in the swamps of Arkansas.

The computerized video robot was installed last fall in the hot and wet Cache River National Wildlife Refuge and has been filling hard disks with footage ever since. The disks are regularly removed and inspected by a team hoping for a glimpse of the celebrated bird.

The computer and cameras, housed in waterproof cases, were designed by professors at Texas A&M University and the University of California at Berkeley.

It was Berkeley professor Kenneth Goldberg who came up with the idea after reading newspaper articles about a possible sighting of the bird in 2004. He and Dezhen Song of Texas A&M built the robot, whose software can distinguish birds from other flying objects such as bats and insects and turns on its two digital cameras only when it identifies a bird.

The work, which Goldberg described at a meeting of the American Association for the Advancement of Science, is funded by the National Science Foundation and supported by several private organizations and companies.