It is the most common large dark swallow in the temperate zone. Its reproduction period is between January and August and it is found mainly between 2,100 and 3,500 m above sea level. Its name Orochelidon means mountain swallow and derives from the Greek roots oros = mountain and chelidon = swallow. Its murine epithet derives from the Latin murinus = mouse gray color.
It measures 14 cm and weighs around 12.5 g. The male has a blackish crown and upper parts with lustrous blue, dark brown wings and tail. Its tail is moderately forked and the underparts grayish brown. The female and young are more opaque than the adult male.
It differs from the Blue-and-white Swallow (Notiochelidon cyanoleuca) in size and totally dark in appearance.
Three subspecies N. m are recognized. meridensis, N. m. murina and N. m. cyanodorsalis. Only the nominal subspecies is found in Colombia.
It is a strictly South American species that is found in Venezuela, Colombia, Ecuador, Peru and Bolivia. In Colombia it is found between 2,100 and 3,500 m above sea level in the Sierra Nevada de Santa Marta, Serranía del Perijá, in the south of the Centran mountain range to Cundinamarca, in the Central mountain range and in the extreme north of the Occidental mountain range. .
It inhabits open highland areas up to the limit of arboreal vegetation, generally near bodies of water. Also in grasslands, crops and close to human dwellings.
Little known, however it is likely that like other swallows it feeds on insects.
Mainly between September and October in Colombia and Ecuador. Individuals in reproductive condition have also been recorded between January and August in the Andes. Build a nest with dry grass, moss, and feathers which you place in a hole, cliff, caves, or under constructions such as bridges or eaves of house roofs. It lays 2 or 3 eggs and everything concerning the incubation and rearing period is unknown.
They forage singly or in small groups, sometimes with Pygochelidon cyanoleuca. It performs fast and direct flights generally low very close to the ground, sometimes high and often in wide circles. It is a resident bird although it is likely to make local movements.
Sometimes included in the genus Notiochelidon or Atticora
It is considered as a least concern