Breeding

Breeding period varies significantly depending on location. In Colombia evidence of nesting has been reported in January and February in the Macarena Mountains (nestlings; Olivares 1962), in the upper Magdalena valley (nest; Miller 1947), and at the mouth of Río Cauca (Hilty and Brown 1986). In the Orinoco region of Venezuela, however, they have been observed breeding February-April (Cherrie 1916). ffrench (1991) found seven nests in Trinidad between April and August, and nesting is reported in July and August in French Guiana (Tostain et al. 1992). In southern Brazil, breeding has been reported in November (Belton 1985).

White-winged Swallows favor crevices as nesting sites, but a large number of nest locations have been recorded. Nest sites include crevices in tree stumps, between rocks or boulders, in cliffs, eaves of houses, pipes, or old woodpecker holes (Turner and Rose 1989, ffrench 1991, Hilty and Brown 1996). Nesting on active ferries has been reported both in French Guiana (Tostain 1979) and and in southern Brazil (Belton 1985).

Nests are compiled of  dried grass and/or roots, often lined with feathers of any number of species. Different clutch sizes have been recorded in various locations, but ranges from 3-6 white eggs. Cherrie (1916) gave the measurements (m) of one set of eggs from Venezuela as 18 x 13.5; 17.5 x 13.5 ; 17.25 x 13.5 and 17 x 13.25. Turner and Rose (1989) give summary data on the eggs as 17-20 mm x 13-14.6 mm, with a mass of 1.9 grams.

Biparental care is common among swallows but incubation and nestling periods have not been recorded specifically for White-winged Swallow. Generally speaking, swallow incubation periods range from 11-20 days, with a 14-16 day period being most common (Turner and Rose 1989). Most swallow eggs don't hatch at the exact same time, and will instead hatch over a period of a couple of days  revealing nestlings with very little down at first (Tuner and Rose 1989).  Generally speaking, the swallow nestling period is between 17 and 30 days, although weather and food scarcity can cause it to be prolonged (Turner and Rose 1989).