Jacopo Cerri , Ilaria Fozzi, Davide De Rosa, Mauro Aresu, Marco Apollonio, Fiammetta Berlinguer

Wind energy is developing on Mediterranean islands, where endangered populations of Griffon Vulture (Gyps fulvus) occur. As griffons are subjected to collisions with wind turbines while foraging, it is necessary to understand which factors affect their movements, to minimize the potential impact of wind farms.
We assessed habitat use by 37 griffons (n. GPS locations = 130,218) and its overlap with wind farms in Sardinia (Italy), an island where griffon vulture population is increasing thanks to concrete conservation actions and wind energy is significantly expanding.
Griffons in Sardinia cover smaller areas (95% isopleth = 956.3 ± 677.7 km2, 50% isopleth = 73.8 ± 48.2 km2) than in mainland Europe, restricting most of their movements within 5-10 km from colonies and roosts.
Concentrated movements aligned with the fact that around roosts and colonies, approx. 20 tons of carrion (21% of estimated available carrion) are provided each year in supplementary feeding stations, while griffons still have enough cliffs to breed. Therefore, our results are highly suggestive that resource availability can constrain griffon movements on Mediterranean islands.
Overall, 6 wind farms out of 29 were built in areas that were covered by moving griffons. Two of them were positioned right outside the areas the most used as foraging grounds, around roosts and supplementary feeding stations.
As griffon movements concentrate around nesting/roosting sites and feeding stations, wind farms should not be built in a buffer zone around these highly utilized areas, and mitigation measures, including the removal of livestock carrion, should be adopted for those that are built at greater distances. There is also an urgent need for updated data about wind energy development. The creation of supplementary feeding stations could be used to shape the enlargement of the foraging grounds of an increasing Griffon Vulture population on Mediterranean islands and to mitigate wind farms impacts.