Bat fatalities at two wind farms in Tasmania, Australia: bat characteristics, and spatial and temporal patterns

Abstract

Bat carcasses from two wind farms in Tasmania (2002Á2010) were assessed to determine the species, sex, age, reproductive state, morphometrics, presence of food in the gastrointestinal tract, and evidence of spatial and seasonal patterns. Thirty-eight of the 54 carcasses were Gould's wattled bats, with another 14 likely to be, and two Vespadelus sp. All but two were adults, with an equal ratio of females and males. None were actively breeding when found, and five of the six bats tested, had not been recently feeding. Mortalities predominantly occurred in autumn, with a small difference between sites. There was no pattern in the location of carcasses. There appear to be particular ecological, morphological and behavioural characteristics associated with bat collision risk*tree roosting bats with high wing aspect ratios that forage in the open air at high altitude appear to be susceptible. Seasonal patterns may be associated with specific behaviours.

Impacts of Wind Energy Development on Bats: A Global Perspective

“…Interestingly, Grodsky (2010) found that bat fatalities were actually lower near the Horicon Marsh in Wisconsin. Hull and Cawthen (2012) found no relationships between bat fatalities and proximity of turbines to the coast or vegetation. Hence, correlating high-risk locations with particular habitat types or topographic patterns has proven difficult and inconsistent.…”

“…Such consistent temporal patterns of fatality are helpful when predicting high-risk periods and applying some mitigation measures such as raising turbine cut-in speed ). Hull and Cawthen (2012) noted that fatalities predominantly occurred in autumn in Tasmania, where the climate is temperate. However, in the tropical Isthmus of Tehuantepec in Mexico, while 46 % of bat fatalities were found in the summer rainy season, no clear pattern in bat deaths associated with any season emerged.…”

“…Little work had been done in the region since this pioneering discovery, until Hull and Cawthen (2012) surveyed two wind facilities in Tasmania, where they recorded 54 bat fatalities from two species, Gould's wattled bats (Chalinolobus gouldii) and an unknown Vespadelus sp. More recently, Bennett (2012) found white-striped free-tailed bats at two turbines located in Victoria.…”

Effects of Renewable Energy Production and Infrastructure on Wildlife

“…The fi rst reports of bat fatalities at wind farms occurred in North America and Europe during the 1990s (Kunz et al 2007 ;Rydell et al 2010 ). However, the occurrence of bat fatalities at wind farms is a global phenomenon with cases described from numerous countries including Australia (Hull and Cawthen 2013 ) and South Africa (Doty and Martin 2013 ). The lack of information on the impact of wind farms on bat populations refl ects the severity and poor understanding of the problem.…”

“…There are no consistent sex or age biases in bat mortality during these periods (Arnett et al . 2008 ;Rydell et al 2010 ;Hull and Cawthen 2013 ). Young bats are not more vulnerable despite their typical dispersal behavior and expected lack of experience.…”