Diving Ducks

These ducks generally dive for food.

The Marbled Duck (Marmaronetta angustirostris) lives in Spain and north Africa east to west China. It is a mottled pale duck with a brown face mask and head tuft.

There are 3 species in the genus Netta.

• Red-crested Pochard (Netta rufina) of Eurasia and north Africa – the male has a chestnut head, red bill, black breast, white flanks, brown back, black rear; the female is brown with a pale face and a dark bill with yellowish/reddish tip; the non-breeding male is like the female, but with red bill.
• Rosy-billed Pochard (N. peposaca) of South America – the male is black with grey flanks and red bill with a knob at the bill base; the female is brown with a dark back and a dark bill.
• Southern Pochard (N. erythrophthalma) of South America and Africa – the male is dark with a pale bill; the female is brown with pale face and brown cheek.

Male Red-crested Pochard in Austria ©Con Foley

Male Rosy-billed Pochard in Jurong Bird Park, Singapore ©Tan KH

Canvasback (Aythya valisineria) has a distinctive feature: the forehead and the culmen forms an almost straight line. Plumage-wise, it looks like the following two ducks.

The Redhead (A. americana) and Common Pochard (A. ferina) look alike, but the former is found in New World, while the latter in the Old World.

Male Common Pochard in Japan ©Con Foley

Female Common Pochard in Sweden ©Con Foley

The Hardhead (A. australis) is an Australasian duck. The male has white eyes, but the female has dark eyes.

Hardhead (male back, female front) in Adelaide, Australia ©Tan KH

The Madagascan Pochard (A. innotata) is only found on Madagascar.

The Ferruginous Duck (A. nyroca) has a duck of Eurasia and Africa. It is reddish overall with a white belly patch; the head being more brilliant red in the male. The male has white eyes, but the female has dark eyes.

Ferruginous Pochard in Thailand ©Con Foley

The Baer’s Pochard (A. baeri) is a very rare duck breeding in southeastern Russia and northeastern Asia; wintering south to India and Southeast Asia. It is like the Ferruginous Duck, but the male has a dark green head.

The following 5 species look alike, but could be distinguished by the amount of white in a generally dark plumage.

• New Zealand Scaup (A. novaeseelandiae) is endemic to New Zealand – unlike other scaups, it has an all-dark plumage.
• Tufted Duck (A. fuligula) of the Old World – the male is black with white flanks and belly; the female is all brownish.
• Greater Scaup (A. marila) of North American and Eurasia – the male has a greyish back, iridescent dark greenish head, larger nail at bill tip and whiter flanks; the female has a white facial patch at the bill base.
• Lesser Scaup (A. affinis) of North America – the male has a greyish back, iridescent dark purplish head, smaller nail at bill tip and dirty-white flanks; the female has a white facial patch at the bill base. In both sexes, the back of the head is more angled than in Greater Scaup.
• Ring-necked Duck (A. collaris) of North America – the male has a black back; unlike other scaups, the bill is not all bluish, but has two white bands for male and one for female; the female has pale eye ring.

New Zealand Scaup (female left, males middle and right) in New Zealand ©Tan KH

Male Tufted Duck in Japan ©Yamane Yoshio

Female Tufted Duck in Japan ©Yamane Yoshio

Male Greater Scaup in Japan ©Con Foley

Female Greater Scaup in Japan ©Con Foley

Lesser Scaup in ID, US ©Tan KH

Reference
http://www.worldbirdnames.org/ioc-lists/master-list-2/