Individually Marked Eurasian Griffon Vulture (Gyps fulvus) Occurrence Phenology in the Eastern Rhodopes, Bulgaria.

The Eurasian Griffon Vulture is a large raptor species with a vast range. The species is breeding in Bulgaria and its population is estimated at more than 100 pairs distributed in several sites in the country nowadays. The aim of the current study was to track the resighting frequency, age and phenology of presence of marked Griffon Vultures in the Eastern Rhodopes, Bulgaria and possibly to record the origin of the tagged individuals. During the study (n=10 years) we recorded 1888 observations of 231 marked Griffon Vultures in total. The number of vulture resightings was 42 ± 8.4 marked individuals per year. The age of 80% of the recorded Griffon Vultures was established. Adult vultures had the highest resighting rate (0.35 ± 0.03). Most of the observed marked Griffon Vultures were recorded during the autumn season, especially the immature birds. The largest portion (n = 1343 resightings) were of Griffon Vultures marked in different parts of Bulgaria. Our results can be easily complemented with GPS telemetry data to reveal entirely movement ecology of Griffon Vulture in the Eastern Rhodopes. [ABSTRACT FROM AUTHOR]