Golondrina Barranquera

The blue-and-white swallow (Pygochelidon cyanoleuca) is a passerine bird that breeds from Nicaragua south throughout South America, except in the deserts and the Amazon Basin. The southern race is migratory, wintering as far north as Trinidad, where it is a regular visitor. The nominate northern race may have bred on that island. == Taxonomy == The blue-and-white swallow was first formally described as Hirundo cyanoleuca by the French ornithologist Louis Pierre Vieillot in 1817, based on a specimen he believed to be from Paraguay. The scientific name has the same meaning as the English common name. This species was formerly placed in the genus Notiochelidon. It was moved to the resurrected genus Pygochelidon based on a phylogenetic study published in 2005. Three subspecies are recognised: P. c. cyanoleuca (Vieillot, 1817) – Costa Rica through northern, central South America P. c. peruviana Chapman, 1922 – western Peru P. c. patagonica (d'Orbigny & Lafresnaye, 1837) – southern South America == Description == The adult blue-and-white swallow averages 11–12 cm (4.3–4.7 in) long and weighs about 10 g (0.35 oz). It has dark blue upperparts and white underparts, and its underwings and the undersurface of its short forked tail are blackish. The juvenile…