Bat carcasses from two wind farms in Tasmania (2002–2010) 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.