Dark-sided Flycatcher

Dark-sided Flycatcher (Muscicapa sibirica) is a small sombre flycatcher with dark grey-brown upperparts, a smudged grey breast, pale belly and fine pale eye-ring. 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 widely in the East Palearctic, waits upright on forest perches before making short flights after insects and migrates south to warmer Asian forests for winter. 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).