A balanced solution to the cumulative threat of industrialized wind farm development on cinereous vultures (Aegypius monachus) in south-eastern Europe.

Wind farm development can combat climate change but may also threaten bird populations' persistence through collision with wind turbine blades if such development is improperly planned strategically and cumulatively. Such improper planning may often occur. Numerous wind farms are planned in a region hosting the only cinereous vulture population in south-eastern Europe. We combined range use modelling and a Collision Risk Model (CRM) to predict the cumulative collision mortality for cinereous vulture under all operating and proposed wind farms. Four different vulture avoidance rates were considered in the CRM. Cumulative collision mortality was expected to be eight to ten times greater in the future (proposed and operating wind farms) than currently (operating wind farms), equivalent to 44% of the current population (103 individuals) if all proposals are authorized (2744 MW). Even under the most optimistic scenario whereby authorized proposals will not collectively exceed the national target for wind harnessing in the study area (960 MW), cumulative collision mortality would still be high (17% of current population) and likely lead to population extinction. Under any wind farm proposal scenario, over 92% of expected deaths would occur in the core area of the population, further implying inadequate spatial planning and implementation of relevant European legislation with scant regard for governmental obligations to protect key species. On the basis of a sensitivity map we derive a spatially explicit solution that could meet the national target of wind harnessing with a minimum conservation cost of less than 1% population loss providing that the population mortality (5.2%) caused by the operating wind farms in the core area would be totally mitigated. Under other scenarios, the vulture population would probably be at serious risk of extinction. Our 'win-win' approach is appropriate to other potential conflicts where wind farms may cumulatively threaten wildlife populations.

Estimation of normal tear production in free-living Eurasian black vultures (Aegypius monachus) and griffon vultures (Gyps fulvus) in Dadia National Park, Greece.

The aim of this study was to record the Schirmer tear test I (STT I) measurements in free-living vultures in order to estimate normal values. The Eurasian black vulture (Aegypius monachus), which breeds in the Mediterranean region and Asia, is listed as near threatened; it is also classified as vulnerable at the European level and endangered in Greece. The griffon vulture (Gyps fulvus), once widespread across the continent, has undergone a dramatic decline which has led to its extinction in many regions. Sixty-two animals were examined in total including 54 black vultures and 8 griffon vultures. The birds were classified into five age groups while four age groups were then combined into one large group: free-flying. STT I measurements and complete ophthalmic examinations were performed. Mean STT I value for black vultures was 10.9 +/- 3.3 mm/min (right eye, oculus dexter, OD) and 11.9 +/- 3.3 mm/min (left eye, oculus sinister, OS) and for griffon vultures was 6.4 +/- 1.8 mm/min OD and 6.5 +/- 1.8 mm/min OS. In both eyes, STT I values in black vultures were significantly higher than those recorded in griffon vultures. Intraspecific comparisons yielded a significant difference between eyes of black vultures but not between those of griffon vultures, with OS producing higher STT I readings than did OD. When STT I was compared between OD and OS for each age group separately, a statistically significant difference was detected in the immature and free-flying black vultures. In addition, black vulture hatchlings had a significantly higher tear production than did free-flying juveniles, immatures, subadults, and adults. STT I values in black vultures are similar to those reported in other Accipitriformes but are lower in griffon vultures. This difference is probably related to anatomic, evolutionary, and feeding factors and requires further investigation.