Rosy-billed Pochard

ID Features: Adult male has a red bill with swollen knob at the base. Glossy black head and upperparts. Gray flanks, bordered by black ventral band and white undertail-coverts. In flight, black coverts with contrasting white remiges tipped black. Underwing mainly whitish. Strong flier; sometimes in V-formation. 
Adult female has a gray bill. Dark brown crown contrasts with paler brown face and neck. White chin and throat; sometimes with a white eye-ring. White vent. In flight, as male, but coverts brown. 
Habitat: Generally found in fresh and saline wetlands with abundant vegetation. 
Locations:   Argentina, Chile