The BSPB (Bulgarian Societey for the Protection of Birds) website publishes a study on the mortality of the Egyptian Vultures monitored by telemetry as part of the Life Return of Neophron project.
Since 2010 28 birds have been tracked by GPS tag. At the end of 2016 21 juveniles out of 23 died as well as 2 adults out of 5.
The study shows that poor navigation during the overflight of the Mediterranean represents the greatest cause of mortality of young people (43%). Six birds died of unknown causes but at least three were hunted.
Dowload study 1489392848_1.pdf