
Photo: (c) Михаил Малышев, some rights reserved (CC BY) · CC BY 4.0
Anser erythropus
Rare visitor: recorded only occasionally in this country
Lesser White-fronted Goose (Anser erythropus) is a small grey goose with a white forehead, yellow eye ring and black belly bars. The combination of body shape, bill structure, plumage pattern and voice provides the most useful field characters. Age, sex and season can alter its appearance, so identification should use several features rather than colour alone. This supports comparison with similar species in the field (Wikipedia, general species account).
It breeds on northern tundra and forest-tundra and migrates to grasslands, wetlands and agricultural feeding areas. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds more likely to gather where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant, visitor or introduced bird (Wikipedia, general species account; Wildlife of Japan occurrence records).