Eurasian coot; common coot
A waterbird (Fulica atra) with a white bill and frontal shield, found in wetlands across Eurasia. In Japanese, usually written in katakana as オオバン.
In winter, coots gather at the lake.
The name オオバン (大鷭) literally means 'large coot' or 'great coot', distinguishing it from smaller rail species. The exact historical derivation is uncertain.