Eastern Yellow Wagtail

Eastern Yellow Wagtail (Motacilla tschutschensis) is a slender long-tailed wagtail whose breeding males generally show bright yellow underparts and an olive or grey-toned head. Body shape, bill structure, plumage pattern and voice provide the strongest field characters. Age, sex and season may alter its appearance, so identification should combine several features and careful direct field comparisons with similar species in the same habitat (Wikipedia, general species account).

It breeds across the eastern Palearctic and Alaska, uses wet meadows and marshy ground for insects and migrates south to South Asia and Australia outside the breeding season. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant or visitor (Wikipedia, general species account; Wildlife of Japan occurrence records).