Mallard vs White-headed Steamerduck

Female gives the classic 'quack-quack-quack', descending in pitch. Male utters soft nasal 'raeb-raeb'. Both give a high 'gag-gag-gag' when alarmed or taking flight.

A deep, rattling call from Patagonian coastal habitat. VU status; calls similar to Magellanic Steamerduck but possibly subtly distinct. Vocalizations in wild remain understudied.

Breeding males have an iridescent green head, white neck ring, chestnut breast, and grey body. Females are mottled brown. Both sexes show a blue speculum bordered by white.

Broad, flat bill — yellow-green in males, orange-brown in females

Flightless. Males have white head and neck contrasting with dark gray-brown body; orange bill. Females brown with white facial markings and less contrasting head. Restricted to Chubut, Argentina coast.