To: whitepine  who wrote (6 ) 8/14/2010 12:02:32 PM From: longnshort  1 Recommendation   Respond to    of 43  Bat Fatalities at Wind Turbines: Investigating the Causes and y Wind energy facility in Colorado. Photo: Paul Cryan/USGSIn the push to develop new forms of sustainable energy, the wind power industry is at the forefront. Turbines that harness the power of wind already serve as effective power sources across the globe, and this proven effectiveness has led to vast increases in the number of turbines currently under construction. The general impact of wind turbines on the environment is likely far less than that of conventional power sources. However, recent evidence shows that certain species of bats are particularly susceptible to mortality from wind turbines. Bats are beneficial consumers of harmful insect pests, and migratory species of bats cross international and interstate boundaries. Dead bats are turning up beneath wind turbines all over the world. Bat fatalities have now been documented at nearly every wind facility in North America where adequate surveys for bats have been conducted, and several of these sites are estimated to cause the deaths of thousands of bats per year. This unanticipated and unprecedented problem for bats has moved to the forefront of conservation and management efforts directed toward this poorly understood group of mammals. The mystery of why bats die at turbine sites remains unsolved. Is it a simple case of flying in the wrong place at the wrong time? Are bats attracted to the spinning turbine blades? Why are so many bats colliding with turbines compared to their infrequent crashes with other tall, human-made structures? Close up of hoary bat (Lasiurus cinereus). Photo by Paul Cryan Photo of a silver-haired bat. Photo by Keith Geluso. Hoary bats (Lasiurus cinereus; left) and Silver-haired bats (Lasionycteris noctivagans; right) are showing up dead beneath wind turbines all across North America. Photos by Paul Cryan and Keith Geluso. USGS Research Biologist Paul Cryan takes a female hoary bat out of a net. This bat was intercepted during its spring migration through New Mexico. Photo by Leslie Cryan. Photo of a hoary bat (Lasiurus cinereus) in a tree. Photo by Paul Cryan. USGS Research Biologist Paul Cryan takes a female hoary bat out of a net. This bat was intercepted during its spring migration through New Mexico. Photo by Leslie Cryan. Like this hoary bat (Lasiurus cinereus), most of the bats killed by wind turbines roost in trees during summer. Photo by Paul Cryan. Although these questions remain unanswered, potential clues can be found in the patterns of fatalities. Foremost, the majority of bats killed by wind turbines are species that rely on trees as roosts throughout the year and migrate long distances; we call these species “migratory tree bats.” Currently, migratory tree bats compose more than three quarters of the bat fatalities observed at wind energy sites. The other striking pattern is that the vast majority of bat fatalities at wind turbines occur during late summer and autumn. This seasonal peak in fatalities coincides with periods of both autumn migration and mating behavior of tree bats. Seasonal involvement of species with shared behaviors indicates that behavior plays a key role in the susceptibility of bats to wind turbines, and that migratory tree bats might actually be attracted to wind turbines.fort.usgs.gov