Study Finds Manatees Have Keen Hearing

Photo courtesy of SaveTheManatee.org

"Manatees can hear 10 times better than humans underwater, a new study suggests. The discovery leaves researchers wondering why so many get hit by boats.

Very little is known about manatees' hearing ability, so researchers tested the range of sound frequencies the creatures could hear using a technique similar to what doctors use to check hearing abilities of newborn humans.

It turns out that manatees, sometimes described as ugly sea cows, are able to follow sounds changing at rates of up to 1,400 cycles per second, with peak responses at 150 and 600.

"This is remarkably ten times faster than that of humans but only half that of dolphins," said study leader David Mann of the University of South Florida.

There are an estimated 3,500 manatees in Florida waters. Despite their excellent hearing, between 70 and 80 are killed by boats each year. Scientists have wondered if they are good at locating where a sound is coming from."
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