herring gull
Refers specifically to the herring gull (Larus argentatus).
海岸でセグロカモメが魚を捕まえていた。
A herring gull was catching fish at the shore.
The word is usually written in kana; this katakana form is standard for bird names.
Kanji form is rare; the bird name is normally written in kana.
Compound of 背黒 (seguro, 'black-backed') and 鴎 (kamome, 'gull'), describing the bird's appearance.