Drake Rosybill Pochard from South America with red eye, massive black-tipped red bill and, in sunlight, purple head.

Although both from South America, the Rosybill Pochard and Chiloe Wigeon make an unlikely couple

The bill has a face-shield

Rosybill Pochard pair

The female Rosybill Pochard has a lesser version of the raised face-shield on her beak

Both genders have white rumps

His grey flanks and black upper back are "vermiculated" (made up of very fine grey/white or black/grey wavy lines)

Comparison to bill of Shelduck