Results of the re-introduction of the Griffon Vulture (Gyps fulvus) in Vrachanski Balkan Nature Park, Bulgaria – completion of the establishing phase 2010–2020

By

Stoyanov, Georgi
Peshev, Hristo
Kmetova–biro, Elena
Stoynov, Emilian
Ivanov, Ivelin
Vangelova, Nadya
Nikolova, Zlatka
Mitrevichin, Emanuil
Grozdanov, Atanas

Type

Article

Date of Publication

2023-04-04

Original Publication

Biodiversity data journal

Volume

11

Pages

1--20

Subjects

acclimatisation , Conservation , feeding site , Home range , raptor , re-establishment , releases , Vrachanski Balkan SPA

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft Publishers [2013]-

Identifiers

DOI: https://doi.org/10.3897/BDJ.11.e100834
eLocator: e100834

 

Abstract

The current study analyses and presents the results of the ten-year establishment phase of the Griffon Vulture (Gyps fulvus) local re-introduction in Vrachanski Balkan Nature Park, north-western Bulgaria. Between 2010 and 2020, 61 rehabilitated and captive-bred Griffon Vultures from Spain, France and several European zoos were released from an acclimatisation aviary. The first successful breeding in the wild was reported in 2015. Thus, the species has been restored as a nesting species in the area after more than 60 years of absence. In 2020, the local population accounted for some 55–70 individuals, consisting of about 20–23 breeding pairs in three-five separate colonies and two frequently-used roosting sites. Forty-two chicks fledged from 2010 to 2020, at an average breeding success of 0.46 chicks/territorial pair and productivity of 0.62 fledglings/breeding pair. The mortality rate is calculated at 0.34; an additional 0.07 of the released individuals have never been seen or found. The local nucleus of the Griffon Vulture now covers a territory of 1,478.58 km², calculated as a 95% home range, while the 50% core area is 9.07 ± 5.73 km2 (range 2.12–22.89 km2). With these results, we consider the establishment phase of the re-introduction of the species in Vrachanski Balkan Nature Park as completed.