A small dark blue-black swallow with rufous-chestnut on its face and a short tail. Except for a black triangular eye-stripe extending to the bill, the entire forehead, chin, throat, and upper breast are rufous-chestnut, without any dark necklace like that of Barn Swallow, the main confusion species. Hill Swallow’s dark upperparts have a blue-green sheen that is only visible when seen up close, while the underparts are dingy white with ashy-gray on the flanks. Juveniles have duller chestnut on the face. Mainly inhabits open areas such as grasslands, reservoirs, and tea estates in the high hills above 500 meters of elevation; very rare at lower elevations. Often seen wheeling and looping in the air after insects, with a swift flight action reminiscent of a Barn Swallow with a shorter tail.