We often saw these attractive swallows perched on snags in the river. They differ from all similar swallows by the extensive white patches on the upper surface of their wings. This is an adult. Sexes are similar but immatures are gray-brown above and their breast is dusky. This species occurs throughout most of northern South America east of the Andes. Their closest relative is the Mangrove Swallow (Tachycineta albilinea) which replaces it in Central America. Canon PowerShot SX60 HS.
References:
Sedgwick, C. W. (2010). White-winged Swallow (Tachycineta albiventer), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.whwswa1.01
Turner, A. (2019). White-winged Swallow (Tachycineta albiventer). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/57706 on 20 July 2019).