Long-term size and range changes of the Griffon Vulture Gyps fulvus population in the Balkans: a review

Abstract

Summary The Eurasian Griffon Vulture Gyps fulvus is a large Palearctic, Indohimalayan and Afrotropical Old-World vulture. The species’ range is vast, encompassing territories from the Pyrenees to the Himalayas. We reviewed and analysed a long-term data set for Griffon Vulture in the Balkans to estimate the change in its population size and range between 1980 and 2019. After a large historical decline, the Griffon Vulture population slightly increased in the last 39 years (λ = 1.02) and reached 445–565 pairs in 2019. We recorded a gradual increase of Griffon Vulture subpopulations in Serbia (λ = 1.08 ± 0.003), Bulgaria (λ = 1.08 ± 0.003) and Croatia (λ = 1.05 ± 0.005) and steep to a moderate decline of the species subpopulations in Greece (λ = 0.88 ± 0.005) and North Macedonia (λ = 0.94 ± 0.01). However, species range contracted to half of its former range in the same period. It occurred in 42 UTM squares in the 1980–1990 period and only 20 UTM squares between 2011 and 2019 and concentrated into three source subpopulations in Bulgaria, Serbia, and Croatia. Following reintroductions of the Griffon Vulture in Bulgaria, new colonies were formed at three novel localities after 2010. Regular movements of individuals between the different subpopulations exist nowadays. Therefore, preservation of both current and former core areas used for breeding and roosting is essential for species conservation in the region. However, the Griffon Vulture still faces severe threats and risk of local extinction. Various hazards such as poisoning, collision with energy infrastructure, disturbance and habitat alteration are depleting the status of the Balkan population and its full recovery. Further studies should analyse age-specific survival and mortality, recruitment, genetic relatedness, spatial use to inform the viability of this population in the future.

Seasonal and age-specific dynamics of the Griffon Vulture’s home range and movements in the Eastern Rhodopes

“…We found that the core of the home range encompasses the species breeding sites along the Arda river valley in Bulgaria, the central feeding station and two small feeding stations, and the Boynik ridge. Along that ridge occur most of the vulture feedings on natural carcasses found in the field (Arkumarev et al 2021a). The Griffon Vultures frequently visited also the central feeding station near the village of Dadia, which is managed by the Management Body of Dadia-Soufli-Lefkimi Forest National Park (DSLFNP).…”

“…The Griffon Vultures frequently visited also the central feeding station near the village of Dadia, which is managed by the Management Body of Dadia-Soufli-Lefkimi Forest National Park (DSLFNP). Vultures foraged also along the Filiouri river and the villages of Esochi and Ragada in Greece where they also frequently find carcasses (Arkumarev et al 2021a). The Kompsatos river valley, northeast from Komothini, was mostly visited by the vultures from spring to autumn.…”

“…In the Balkan Peninsula, the species has undergone a decline during the 20 th century (Andevski 2013). However, over the past 30 years it showed recovery in Serbia, Bulgaria and Croatia (Dobrev et al 2021a). Its population in Bulgaria has steadily increased as a result of intensive conservation actions and successful reintroduction programs (Demerdzhiev et al 2014, Dobrev et al 2021a.…”

“…However, over the past 30 years it showed recovery in Serbia, Bulgaria and Croatia (Dobrev et al 2021a). Its population in Bulgaria has steadily increased as a result of intensive conservation actions and successful reintroduction programs (Demerdzhiev et al 2014, Dobrev et al 2021a. The adult and immature Griffon Vultures are mostly resident, while some juveniles are migratory and winter in the Middle East and Africa (del Hoyo et al 1994, McGrady & Gavashelishvili 2006, Arkumarev et al 2019.…”

“…However, their ranging movements are affected by the availability of food and they tend to concentrate near predictable food sources (Deygout et al 2010, Monsarrat et al 2013, Dobrev et al 2021b). In the Balkans, vultures largely depend on extensively grazed livestock and supplementary feeding stations, which shape their home ranges (Azmanis 2009, Arkumarev et al 2021a. The spatial ecology of the Griffon Vulture has been a subject of scientific interest for long due to its conservation status, critical ecosystem role and complex foraging behavior.…”