Why wind turbines can mean death for batsAugust 26, 2008Power-generating wind turbines have long been recognized as a potentially life-threatening hazard for birds. But at most wind facilities, bats actually die in much greater numbers. Now, researchers reporting in Current Biology, a Cell Press journal, on August 26th think they know why. Ninety percent of the bats they examined after death showed signs of internal hemorrhaging consistent with trauma from the sudden drop in air pressure (a condition known as barotrauma) at turbine blades. Only about half of the bats showed any evidence of direct contact with the blades. "Because bats can detect objects with echolocation, they seldom collide with man-made structures," said Erin Baerwald of the University of Calgary in Canada. "An atmospheric-pressure drop at wind-turbine blades is an undetectable-and potentially unforeseeable-hazard for bats, thus partially explaining the large number of bat fatalities at these specific structures.
"Given that bats are more susceptible to barotrauma than birds, and that bat fatalities at wind turbines far outnumber bird fatalities at most sites, wildlife fatalities at wind turbines are now a bat issue, not a bird issue." The respiratory systems of bats and birds differ in important ways, in terms of both their structure and their function. Bats' lungs, like those of other mammals, are balloon-like, with two-way airflow ending in thin flexible sacs surrounded by capillaries, the researchers explained. When outside pressure drops, those sacs can over-expand, bursting the capillaries around them. Bird lungs, on the other hand, are more rigid and tube-like, with one-way circular airflow passing over and around capillaries. That rigid system can more easily withstand sudden drops in air pressure. The majority of bats killed at wind turbines are migratory bats that roost in trees, including hoary bats, eastern red bats, and silver-haired bats. While little is known about their population sizes, the researchers said, those deaths could have far-reaching consequences. Bats typically live for many years, in some cases reaching ages of 30 or more. Most also have just one or two pups at a time, and not necessarily every year. "Slow reproductive rates can limit a population's ability to recover from crashes and thereby increase the risk of endangerment or extinction," said Robert Barclay, also at the University of Calgary, noting that migrating animals tend to be more vulnerable as it is. All three species of migratory bats killed by wind turbines fly at night, eating thousands of insects-including many crop pests-per day as they go. Therefore, bat losses in one area could have very real effects on ecosystems miles away, along the bats' migration routes. Baerwald said there is no obvious way to reduce the pressure drop at wind turbines without severely limiting their use. Because bats are more active when wind speeds are low, one strategy may be to increase the speed at which turbine blades begin to rotate during the bats' fall migration period. Cell Press Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Huntingtons Disease Bacterium HPV Mental Health Meditation Iron Deficiency Quality Of Life Cognition Asthma AIDS vaccine Bone Formation Lung Function Alcohol Addiction Bats Marijuana Telemedicine Food Poisoning Cancer Drug Cancer Cell Walking Nanowire Anxiety disorder Amniotic Fluid Tumor cell Visual Cortex
See More: Science News Tags | |||||||||||||||||||||
|
Related Bats Current Events and Bats News Articles Spanish scientists develop echo-location in humans A team of researchers from the University of Alcalá de Henares (UAH) has shown scientifically that human beings can develop echolocation, the system of acoustic signals used by dolphins and bats to explore their surroundings. Scientists find a biological 'fountain of youth' in new world bat caves Scientists from Texas are batty over a new discovery which could lead to the single most important medical breakthrough in human history-significantly longer lifespans. Geographic profiling applied to track hunting patterns of white sharks in South Africa Predation is one of the most fundamental and fascinating interactions in nature, and sharks are some of the fiercest predators on Earth. Biologist discovers pink-winged moth in Chiracahua Mountains University of Arizona biologist Bruce Walsh has identified a new species of moth in southern Arizona. Normally, this is not a big deal. Scientists determine geese involved in Hudson River plane crash were migratory Scientists at the Smithsonian Institution examined the feather remains from the Jan. 15 US Airways Flight 1549 bird strike to determine not only the species, but also that the Canada geese involved were from a migratory, rather than resident, population. Bats recognize the individual voices of other bats Bats can use the characteristics of other bats' voices to recognize each other, according to a study by researchers from the University of Tuebingen, Germany and the University of Applied Sciences in Konstanz, Germany. Google Earth aids discovery of early African mammal fossils A limestone countertop, a practiced eye and Google Earth all played roles in the discovery of a trove of fossils that may shed light on the origins of African wildlife. Study assesses impact of fish stocking on aquatic insects The impact fish stocking has on aquatic insects in mountain lakes can be rapidly reversed by removing non-native trout, according to a study completed by U.S. Forest Service and University of California, Davis, scientists. Brown-Led Team Offers First Look at How Bats Land A Brown University-led research team has documented for the first time how bats land. The results are surprising: Not all bats land the same way. The findings, which appear in the Journal of Experimental Biology, could offer new insights into how the second-largest order of mammals evolved. Drug blocks 2 of world's deadliest emerging viruses Two highly lethal viruses that have emerged in recent outbreaks are susceptible to chloroquine, an established drug used to prevent and treat malaria, according to a new basic science study by researchers at Weill Cornell Medical College in the Journal of Virology. More Bats Current Events and Bats News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||