The most extensive data on the nesting biology of Three-striped Warbler are from Yacumbú National Park in the Andes in Lara, Venezuela, where 146 nests were encountered in the course of a five year study (Cox and Martin 2009). At this site, egg laying was initiated from 8 March to 25 June, but the median date of laying of the first egg was 16 May (Cox and Martin 2009). The breeding season in the coastal mountains of Venezuela is similar, April to June (Schäfer and Phelps 1954). At one site in (San Antonio) in the western Andes of Colombia, the breeding season is January-July (MIller 1963). Elsewhere in Colombia, a nest under construction was found on 23 June (Valle del Cauca, Peter Hoell); a nest with eggs was encountered on 29 April in Huila (Hilty and Brown 1986); and a begging fledgling was observed in Valle del Cauca on 18 April (Hilty and Brown 1986).