“…So far as is known, members of the genus Atlapetes build open-cup nests and lay white eggs with cinnamon or vinaceous spotting (Rowley, 1962(Rowley, , 1966Salaman et al, 1998;Oppel et al, 2003;de la Peña, 2005;Biancucci & Martin, 2008;Greeney, 2009;Peraza, 2009;Olaciregui & Botero-Delgadillo, 2012;Forrester & Londoño, 2016). Sparrows in the closely related genus Arremonops (del Hoyo et al, 2018), sometimes merged into Arremon (Phelps & Phelps, 1950;Meyer de Schauensee, 1951) lay unmarked eggs like Nest Group 1, but clearly have nest architecture that is nearly indistinguishable from members of Nest Group 2 (Merrill, 1878;Sennett, 1878;Stone, 1918;Skutch, 1954;Rowley, 1984;Salgado-Ortiz et al, 2001). As mentioned above, A. crassirostris and A. castaneiceps, previously separated in the genus Lysurus fall most readily within Nest Group 2, particularly with respect to nest architecture.…”