Most information on the nesting of White-collared Seedeaters is from Skutch (1954). The White-collared Seedeater nest is composed of fibers, spider webs, fine rootlets, pieces of grass. The shape similar to a slight cup, and is open. The male does not assist the female with building the nest, and the female begins building the nest by finding cobwebs to cover the twigs. After the step of covering the twigs with cobwebs is finished, the female adds grass and fine rootlets to the nest. It takes about five to six days to complete the task of building a proper nest. The amount of lining is very thin, so much so that light can pass through it (Stiles and Skutch 1989, Eitniear and Rueckle 1996, Eitniear 1995). Nests are placed 0.6-3 meters above ground in a shrub or tree. The clutch size is 2-3. The egg is pale blue-gray in color, with dark brown or black mottling or speckles. The average size of the eggs are 16.3 by 12.7 millimeters (n=13, Skutch 1954). The most active time for nesting is April-December (Stiles and Skutch 1989). The female is solely responsible for caring for the eggs during the incubation process, and eggs hatch within about thirteen days. After hatching, the parents care for the young for ten to eleven days. White-collared Seedeater can produce at least three different sets of clutch every year (Skutch 1954).