Wind power may prove to be a promising source of clean energy, but it can also be deadly to bats. Not only can the animals be sliced by the blades of wind turbines, but the sudden drop in air pressure around the turbines can also cause bats’ lungs to explode. An electromagnetic field emitted near the turbines, however, may help bats steer clear of them, according to a new study published in the Public Library of Science One.
Bat casualties near wind turbines have proven to be significant: In 2004, over the course of six weeks, roughly 1,764 and 2,900 bats were killed at two wind farms in Pennsylvania and West Virginia, respectively [LiveScience]. If wind power continues to become increasingly prevalent, so too might the turbines become a growing threat to bat populations. “Given the growing number of wind turbines worldwide, this is going to be an increasing problem, no question about that,” said [co-author] Paul Racey [LiveScience].
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Bats may have a clever way of catching prey, but it turns out the tiger moth has some tricks of its own to avoid becoming a bat’s next meal. According to a study published in Science, the tiger moth disrupts the sound waves the bat uses home in on prey by emitting its own ultrasound blasts.
Researchers knew that the tiger moth emitted ultrasound waves, but they weren’t sure why. Previous studies indicated the moth’s sounds might serve to startle the bats, or warn them that the insects were unpalatable. The new research, however, tested both of these theories. The scientists had so-called big brown bats hunt tiger moths in a chamber fitted with ultrasonic recording equipment and high-speed infrared video. If the moth sound is used to startle bats, then in the chamber the bats should be disrupted on first attack, then learn to ignore the ultrasonic click, the team figured. That didn’t happen. If the moths’ clicks are warnings that the insects taste bad, then the bats should hear the click, bite the moth—and never do so again whenever they hear the sound. That didn’t happen either [National Geographic News].
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A French nuclear submarine has joined the search for the “black box” of Air France Flight 447, which disappeared over the Atlantic last week with all of its 228 passengers. The “black box” is actually an orange cylinder — about 13 pounds of metal wrapped around a stack of memory chips and designed to withstand the force of being slammed high-speed into a brick wall. Actually a pair of devices — the flight data recorder and a voice and audio recorder — the equipment records virtually everything about how an airplane is working [CNN].
Aviation experts hope that the black box, if it can be located on the seafloor, will provide an explanation for what went wrong on the flight, which vanished so mysteriously. On board the French sub, the Emeraude, crewmen called “golden ears” were straining to pick up in their headsets the acoustic pings aircraft black boxes are supposed to transmit for 30 days under water. Nothing is better equipped for such faint sounds than an attack submarine with sophisticated sonar gear for detecting vessels deep in the ocean, naval officers said [Times Online].
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