Sand Martin

Sand Martin (Riparia riparia) is a small brown-and-white swallow with a brown breast band, short slightly forked tail and rapid fluttering flight. 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 feeds on aerial insects above rivers, lakes and open country, nests colonially in tunnels excavated into sandy banks and migrates from Holarctic breeding areas to southern continents 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).