Eastern Red-rumped Swallow

Eastern Red-rumped Swallow (Cecropis daurica) is a small swallow with dark blue upperparts, a rusty-red rump and collar, pale streaked underparts and a deeply notched tail. 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 hunts flying insects above open hilly country and cultivation across eastern Asia and builds a closed mud nest with a tubular entrance beneath cliffs, bridges or buildings. 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).