Re-introduction of Griffon Vulture (Gyps fulvus) in the Eastern Balkan Mountains, Bulgaria – completion of the establishment phase 2010-2020

By

Kmetova–biro, Elena
Stoynov, Emilian
Ivanov, Ivelin
Peshev, Hristo
Marin, Simeon
Bonchev, Lachezar
Stoev, Iliyan
Stoyanov, George
Nikolova, Zlatka
Vangelova, Nadya
Parvanov, Dimitar
Grozdanov, Atanas

Type

Article

Date of Publication

2021-04-20

Original Publication

Biodiversity data journal

Volume

9

Pages

1--20

Subjects

breeding performance , conservation management , establishment , feeding site , GPS tracking , Griffon Vulture , Home range , Kotlenska planina SPA , re-introduction , release , Sinite Kamani Nature Park , source-sink

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft Publishers [2013]-

Identifiers

DOI: https://doi.org/10.3897/BDJ.9.e66363
eLocator: e66363

 

Abstract

The current study presents and analyses the results from the recently completed 11-year-establishment phase, following the start of the local re-introduction of the Griffon Vulture (Gyps fulvus) in Kotlenska Planina SPA and Sinite Kamani Nature Park in the Eastern Balkan Mountains of Bulgaria in the period 2010-2020. As a result of the re-introduction efforts and release of 153 individuals, the Griffon Vulture has been successfully reproducing again in the Eastern Balkan Mountains since 2016, after more than 40-50 years of absence. At 2020, the local population consists of some 80 local and up to 80-115 birds, together with sojourn individuals. Amongst them, 23-25 breeding pairs, located in five different colonies and two more frequently used roosting sites. The current average productivity remains relatively low: 0.41 fledglings/territorial pair and fledging success of 0.61 fledglings/breeding pair between 2016 and 2020, but shows a trend to increase with time and the growing experience of the young locally re-introduced population. The mortality confirmed between 2010-2021 accounts for 33%, mostly due to electrocution as a post-release effect in the first six months following their release. Our data show that the newly established population in the Eastern Balkan Mountains mostly forages on feeding sites, having a comparatively small 95% home range: 281.88 ± 91 km2 and 50% core area: 6.6 ± 2.28 km2 (range 4.7–8.5 km2). We, therefore, consider the establishment phase of the re-introduction of Griffon Vulture in this particular site as successfully completed, but management should continue. Furthermore, the area of the Eastern Balkan Mountains can currently be regarded as a source for the species within the source-sink population regulation concept in the national and Balkan context.