Coues' gadwall

Coues' gadwall or Washington Island gadwall (Anas strepera couesi) is an extinct dabbling duck which is only known by two immature specimens from the Pacific island of Teraina,Line Islands, Kiribati. They are in the National Museum of Natural History in Washington, D.C.. The bird was named in honor of Elliott Coues.

Description

A male and a female are known, which resemble the immature appearance of the common gadwall except for the black bill with a higher number of fuiltering lamellae, black feet, and the much inferior size (which may be due to the birds not being fully grown). The male resembles a male common gadwall in eclipse plumage save for some white speckling on the breast and back. The female looks like a small common gadwall female; the primary wing coverts were not patterned black, and the inner web of the secondary remiges was grey instead of white.

Measurements are: wing, 19.9 cm; bill, 3.7 cm; tarsus 3.6 cm. This means the birds were the size of a Cape teal or garganey, with a total length of 40–45 cm. As the birds were not fully adult when shot, it is not clear whether they would not have grown a bit larger.