Berkeley -- A species of ant native to Central and South America is entering the annals of extreme animal movement, boasting jaws arguably more impressive than such noteworthy contenders as the great white shark and the spotted hyena.
Biologists clocked the speed at which the trap-jaw ant, Odontomachus bauri, closes its mandibles at 35 to 64 meters per second, or 78 to 145 miles per hour - an action they say is the fastest self-powered predatory strike in the animal kingdom. The average duration of a strike was a mere 0.13 milliseconds, or 2,300 times faster than the blink of an eye.
A research team led by Sheila Patek, assistant professor of integrative biology at the University of California, Berkeley, calculated the kinematics of the trap-jaw ant's mandible strikes with the help of advances in high-speed videography. The researchers published their results in the Aug. 21 issue of the Proceedings of the National Academy of Sciences.
They found that the jaws, used to capture prey and to defend the ant from harm, accelerate at 100,000 times the force of gravity, with each jaw generating forces exceeding 300 times the insect's body weight. The ants in this study had body masses ranging from 12.1 to 14.9 milligrams.
"You'd think the relevant number is the mandible closing speed, but it's actually the acceleration that is most impressive," said Patek. "The acceleration is huge relative to the tiny mass of the mandibles. The mandibles are operating in the outer known limits in biology in terms of speed and acceleration."
Patek acknowledged that falcons can dive as fast as 300 miles per hour, but that the raptors must start from very high altitudes and get a boost from the force of gravity to reach those speeds. In comparison, animals such as trap-jaw ants and mantis shrimp (which formerly held the record for swiftest strike in the animal world) utilize energy stored within their own bodies. The mandibles of the trap-j
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Contact: Sarah Yang
scyang@berkeley.edu
510-643-7741
University of California - Berkeley
21-Aug-2006