Vol. 78 2026

ARTICLES

Breeding Success of Great Cormorant (Phalacrocorax carbo), European Shag (Gulosus aristotelis) and Yellow-Legged Gull (Larus michahellis) on Giresun Island, Türkiye

Yusuf Can Arslan1, Ahmet Arpacık2,*

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1Graduate School of Natural and Applied Science, Karadeniz Technical University, 61080, Trabzon, Türkiye,
E-mail: yusufcanarslan.28@gmail.com; ORCID: https://orcid.org/0009-0003-9241-0030
*2Department of Wildlife Ecology and Management, Karadeniz Technical University, 61080, Trabzon, Türkiye,
E-mail: ahmetarpacik@ktu.edu.tr; ORCID: https://orcid.org/0000-0001-8053-4253

https://doi.org/10.71424/azb78.2.003000

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Abstract

We studied the breeding success of the Great Cormorant (Phalacrocorax carbo), European Shag (Gulosus aristotelis), and Yellow-legged Gull (Larus michahellis) on Giresun Island, located on the eastern Black Sea coast of Türkiye, during the 2022 and 2023 breeding seasons. We recorded the number of nests on the whole island, and for a subset of nests, we recorded clutch size, nest, egg, and chick survival. Across both breeding seasons, a total of 525 Great Cormorant nests were followed. The mean clutch size was 2.1. The proportion of eggs that hatched (hatching success) was 73.1%, and the proportion of hatched chicks that survived to fledging (fledging success) was 83.6%. The proportion of eggs that resulted in a fledged young (egg-to-fledgling survival rate) was 61.1%. For the European Shag, 75 nests were followed with corresponding success rates of 57.2%, 65.7%, and 37.6%, respectively, with a mean clutch size of 2.8. In the Yellow-legged Gull population, 455 nests were followed, with success rates of 25.6%, 76.3%, and 19.6%, respectively, and a mean clutch size of 2.4. These findings provide valuable insights into the reproductive ecology of these seabird species and contribute to the development of targeted conservation strategies in the Black Sea region.

Key words

breeding biology, chick survival, egg, hatching success, nest, seabirds

How to Cite
Arslan Y. C., Arpacık A. 2026. Breeding success of Great Cormorant (Phalacrocorax carbo), European Shag (Gulosus aristotelis) and Yellow-Legged Gull (Larus michahellis) on Giresun Island, Türkiye. Acta zoologica bulgarica 78.

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