Vol. 76 (2) 2024

ARTICLES

Exceptionally Low Proportion of Adult Pairs and Male-Skewed Adult Sex Ratio in a Declining Population of the Golden Eagle Aquila chrysaetos (L., 1758) (Accipitriformes: Accipitridae)

Ivaylo D. Angelov¹,²

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¹National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd., 1000 Sofia, Bulgaria; E-mail: ivaylo.angelov@nmnhs.com
²Bulgarian Society for the Protection of Birds, Nature Conservation Centre – Eastern Rhodopes, 6480 Madzharovo, Haskovo, Bulgaria

https://doi.org/10.71424/azb76.2.002769

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Abstract
Generally, golden eagles have a favourable conservation status but they are threatened in some parts of their range. A nationwide breeding survey of the golden eagles in Bulgaria found that the species is in a decline. Contrary to the last estimation for 212 pairs, only 93 territories were found occupied while 81 were vacant. Only half of the pairs were in adult plumage and the other half had at least one of the members in non-adult plumage. The adult sex ratio was biased towards males (1.31 males per female), with the male older in 26 out of 33 territories, where the birds differed in their age classes. The obtained results could be explained by a very high unnatural mortality of territorial birds.

Key words
age structure, Bulgaria, raptors

How to Cite
Angelov I.D. 2024. Exceptionally Low Proportion of Adult Pairs and Male-Skewed Adult Sex Ratio in a Declining Population of the Golden Eagle Aquila chrysaetos (L., 1758) (Accipitriformes: Accipitridae). Acta zoologica bulgarica 76 (2) 241-248.

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