Ferruginous Duck
Aythya nyroca
The breeding male is a rich, dark chestnut on the head, breast and flanks with contrasting pure white undertail coverts. In flight the white belly and underwing patch are visible. The females are duller and browner than the males. The male has a yellow eye and the females have a dark eye.
ID text from Wikipedia, CC BY-SA 4.0
Hardhead
Aythya australis
Hardheads are smaller than most ducks, with body length typically between 42–59 cm (17–23 in). Both sexes are similar in size, ranging 525–1,100 g (18.5–38.8 oz) with wingspans of 65–70 cm (26–28 in). Both male and female are a fairly uniform chocolate-brown above, with rufous flanks and white undersides (which are often not visible if the duck is in the water). The trailing edges and almost the entire underside of the wings are white. In the male, the eyes are a striking white, in the female, brown.
ID text from Wikipedia, CC BY-SA 4.0
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