Bluethroat

Bluethroat (Luscinia svecica) is a small brown chat whose male has a brilliant blue throat patch bordered below by black, white and chestnut bands. 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 in wet birch scrub and bushy marsh across the Palearctic and western Alaska, feeds on insects near the ground, nests low in vegetation and migrates to southern Europe, Africa and Asia. 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).