Boa Constrict-o-Meter

Big squeeze. The constrict-o-meter in action.

Another of nature's secrets has been pried from her bosom: Scientists have figured out how to monitor the pressure a boa constrictor exerts while squeezing a rabbit to death.

Engineers at Carnegie Mellon University in Pittsburgh, Pennsylvania, constructed a "constrict-o-meter" at the request of local zookeepers who wanted a visual measure of the snake's coil power for an episode of BBC's Animal Planet. The device, a pressure-sensitive, quarter-sized plate mounted on the end of a 30-centimeter-long probe, is placed between the snake and its prey, says mechanical engineer Adnan Akay, who designed the rig with two assistants. Wires carry the information from the probe to a laptop computer, which plots the pressure. A 5.5-meter python, for example, can create a force of about 1 kilogram per square centimeter on its victim--about six times as rigorous as a firm handshake.

Herb Ellerbrock, who works with the cold-blooded creatures at the Pittsburgh Zoo, says when he approached the Carnegie Mellon engineers with his unusual request, "I thought they'd laugh me out of the room." But the collaboration on the constrict-o-meter worked out so well that he and Akay are planning additional experiments. "Now I'd like to see how many pounds per square inch the small snakes can do," says Ellerbrock.

Related sites
Adnan Akay's home page
Pittsburgh Zoo

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