Breeding status of bird species of Giresun Island

In this study, the breeding statuses of bird species on Giresun Island, with a total area of approximately 4.6 hectares, were determined. A total of 91 days of fieldwork were conducted in and around the island (October 2021-December 2023). Boat transportation was used to access the island, and both direct and indirect observation methods were employed during the fieldwork. On Giresun Island, 102 bird species belonging to 39 families were identified. During the research period, breeding behaviors of species such as Great cormorant (Phalacrocorax carbo), European shag (Gulosus aristotelis), Yellow-legged gull (Larus michahellis), Little egret (Egretta garzetta), Eurasian jackdaw (Corvus monedula), and Eurasian blackbird (Turdus merula) were observed. Nesting sites, population numbers, breeding data, and factors affecting breeding success for Great cormorant, European shag, and Yellow-legged gull in 2022 and 2023 were determined. The highest numbers of individuals recorded were for Great cormorant (638 and 856 individuals in 2022 and 2023), European shag (84 and 136 individuals), and Yellow-legged gull (446 and 462 individuals), respectively. Incubation periods ranged from 28 to 31 days. For Great cormorant, 525 nests, 1116 eggs, and 682 fledglings were identified, with success rates of 61.1%, 73.1%, and 83.6%, respectively. European Shag had 75 nests, 199 eggs, and 75 fledglings, with success rates of 37.6%, 57.2%, and 65.7%, respectively. Yellow-legged gull had 455 nests, 1054 eggs, and 206 fledglings, with success rates of 19.54%, 25.61%, and 76.29%, respectively.