Sparrowlike bird known for gathering in enormous wintering flocks in South America. Males are striking with yellow breast, black patch on throat, and rufous shoulders. Females duller but usually show faint ghost of male's yellow pattern and rufous shoulders. Breeds in grasslands. Feeds on seeds and insects. Wanders during migration and is sometimes found out-of-place among flocks of House Sparrows. Call is a flatulent, buzzy "fpppt," often given in flight.