Carduelis xanthogastraSporagra xanthogastra The yellow-bellied siskin (Spinus xanthogastrus) is a small passerine bird in the finch family Fringillidae.

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.

The yellow-bellied siskin is more of a woodland bird than the superficially similar lesser goldfinch (Spinus psaltria) and the latter species is paler and has a white wing patch and a more musical song.

The yellow-bellied siskin breeds in mountain oak forests at altitudes between 800–3,000 m. The nest is a shallow cup of rootlets, bark and lichens 2.4–3.7 m high in the dense foliage of a small tree in a clearing.

Where it remains common, in remote or protected areas, flocks of up to 30 birds forage in the canopy for small insects and oak flowers, or descend to clearings for seeds.