ML583321551
Common/Arctic Tern Sterna hirundo/paradisaea
Участник
Дата
Местоположение
- Возраст
- Не указано
- Пол
- Не указано
Подробности наблюдения
First summer bird. Small head, no dark secondaries, mostly clean upper primaries with no strong carpal bar and no dark secondaries. Distant photos. Field ID / ID by people on the boat was Arctic Tern. Shopping for opinions, and no one wanted to touch this for a definitive ID, but most people lean towards Common Tern. Structure: Several people thought the bill looks long and is better for Common Tern. This seems to be an ambiguous feature on this bird, and open to interpretation. Plumage: The bird is in molt, having replaced all inner primaries while retaining P9 and P10. These outer primaries are clearly dark, whereas the fresher primaries are not noticeably dark. This is a difficult plumage to judge Common vs Arctic. Some inner secondaries may be retained older feathers and appear darker on the upperwing. On the underwing, the fact that the bird is in molt makes things difficult, but the trailing edge could be interpreted as fairly broad. All in all, perhaps plumage characteristics are not particularly useful for birds in this plumage, and this bird is not structurally obvious (but most people lean towards Common Tern), and a slash is probably the best conclusion.
Техническая информация
- Модель
- NIKON D5600
- ISO
- 800
- Фокусное расстояние
- 500 mm
- Вспышка
- Flash did not fire
- Диафрагма
- f/6.3
- Выдержка
- 1/2500 sec
- Размеры
- 616 pixels x 413 pixels
- Исходный размер файла
- 66.4 KB