Alzavola marezzata Anas flavirostris

Widespread and often common small duck of wetlands, lakes, river mouths, Andean bogs, and streams. Rather small and compact with a dark head, a bright yellow bill (duller for a short while on young birds), and plain grayish sides. The similar Yellow-billed Pintail is larger and more elegant with a paler head and mottled sides. Teal populations in the high Andes (“Altiplano Teal”) have noticeably paler gray sides than southern lowlands birds (“Austral Teal”).