Anthropogenic Factors Are the Major Cause of Hospital Admission of a Threatened Species, the Grey-Headed Flying Fox (Pteropus poliocephalus), in Victoria, Australia.

To determine the reasons for presentation and outcomes of hospitalised grey-headed flying foxes (Pteropus poliocephalus) in Victoria, Australia, a retrospective analysis was performed on 532 records from two wildlife hospitals. Cases were categorised based on presenting signs and outcomes determined. Anthropogenic factors (63.7%) were a major cause of flying fox admissions with entanglement in fruit netting the most significant risk for bats (36.8%). Overall the mortality rate for flying fox admissions was 59.3%. This study highlights the effects of urbanisation on wild animal populations and a need for continued public education in order to reduce morbidity and mortality of wildlife, especially threatened species.

A forensic investigation into the etiology of bat mortality at a wind farm: barotrauma or traumatic injury?

Migrating bats have increased mortality near moving turbine blades at wind farms. The authors evaluated competing hypotheses of barotrauma and traumatic injury to determine the cause. They first examined the utility of lungs from salvaged bat carcasses for histopathologic diagnosis of barotrauma and studied laboratory mice as a model system. Postmortem time, environmental temperature, and freezing of carcasses all affected the development of vascular congestion, hemorrhage, and edema. These common tissue artifacts mimicked the diagnostic criteria of pulmonary barotrauma; therefore, lung tissues from salvaged bats should not be used for barotrauma diagnosis. The authors next compared wind farm (WF) bats to building collision (BC) bats collected near downtown Chicago buildings. WF bats had an increased incidence in fracture cases and specific bone fractures and had more external lacerations than BC bats. WF bats had additional features of traumatic injury, including diaphragmatic hernia, subcutaneous hemorrhage, and bone marrow emboli. In summary, 73% (190 of 262) of WF bats had lesions consistent with traumatic injury. The authors then examined for ruptured tympana, a sensitive marker of barotrauma in humans. BC bats had only 1 case (2%, 1 of 42), but this was attributed to concurrent cranial fractures, whereas WF bats had a 20% (16 of 81) incidence. When cases with concurrent traumatic injury were excluded, this yielded a small fraction (6%, 5 of 81) of WF bats with lesions possibly consistent with barotrauma etiology. Forensic pathology examination of the data strongly suggests that traumatic injury is the major cause of bat mortality at wind farms and, at best, barotrauma is a minor etiology.

How to...handle bats.

Vets are increasingly called upon to answer the public's questions regarding bats, as well as to treat casualties, and have a duty to aid in the VLA's bat surveillance programmes. Here Liz Mullineaux from Quantock Veterinary Hospital and Matt Brash from Battelflatts Veterinary Clinic introduce Companion readers to the techniques and precautions necessary when handling bats.

Type I external skeletal fixation of radial fractures in microchiropterans.

An adult male big brown bat (Eptesicus fuscus) and an adult female hoary bat (Lasiurus cinereus) were presented with open transverse middiaphyseal left radial fractures. Initial repair was attempted by intramedullary pinning. When the fractures did not heal, intramedullary pins were removed and type I external skeletal fixators were placed. The fractures healed, and the big brown bat regained normal flight but the hoary bat did not.