Falcated duck or falcated teal 
(Vịt lưỡi liềm, Mareca falcata)

The falcated duck or falcated teal (Mareca falcata) is a gadwall-sized dabbling duck from the east Palearctic (East Siberia and Mongolia to North Japan; wintering to India).
This dabbling duck is strongly migratory and winters in much of Southeast Asia.

The name of the genus Mareca is from the Portuguese word Marreco for a small duck.
"Falcata" comes from the Latin word falcatus, meaning "sickle-shaped" or "curved like a sickle".