High Quality Content by WIKIPEDIA articles! The Yellow-bellied Siskin, Carduelis xanthogastra, is a small passerine bird in the finch family Fringillidae. It breeds from Costa Rica south to southern Ecuador, central Bolivia and the highlands of northwestern Venezuela. The Yellow-bellied Siskin breeds in mountain oak forests at altitudes between 800 3000 m. The nest is a shallow cup of rootlets, bark, and lichen 2.4 3.7 m high in the dense foliage of a small tree in a clearing. The two or three green-tinged white eggs are laid in April or May and incubated by the female. Although not migratory, this species wanders within its range when not breeding. The Yellow-bellied Siskin is a small bird, 10.5 cm in length and weighing 12 g. The male is entirely black except for a bright yellow belly, tail sides and wing patches.