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.

中文翻译：

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重新引入保加利亚东部巴尔干山脉的狮riff（Gyps fulvus）–完成了2010-2020年的建立阶段

当前的研究提出并分析了最近完成的11年建立阶段的结果，这是在本地重新引入位于巴尔干山脉东部的Kotlenska Planina SPA和Sinite Kamani自然公园中的Griffon Vulture（Gyps fulvus）之后的结果。保加利亚在2010-2020年期间的收入。经过重新引入和释放153个人的努力，格里芬兀ul在缺席40到50年后，自2016年以来已成功地在东部巴尔干山脉再次繁殖。到2020年，当地人口包括约80只本地鸟类和多达80-115只鸟类，以及寄居者。其中有23-25个繁殖对，分别位于五个不同的殖民地和两个更常用的栖息地。当前的平均生产率仍然相对较低：0。在2016年至2020年之间，有41羽雏鸟/领土对和0.61羽雏鸟/育种对的成鸽成功，但是随着时间的增长和本地重新引入的年轻人口经验的增长，趋势呈现出增加的趋势。在2010年至2021年之间确认的死亡率占33％，主要是由于释放后头六个月内因电死而产生的后释放效应。我们的数据显示，巴尔干东部山区新近建立的种群主要在觅食地觅食，其相对较小的95％的家庭范围为：281.88±91 km2，50％的核心面积为：6.6±2.28 km2（范围为4.7–8.5 km2）。因此，我们认为在此特定站点重新引入Griffon Vulture的建立阶段已成功完成，但管理应继续进行。此外，