Pāpango have a variety names both in Māori and English. Matapouri, Titipourangi and Raipo along with Black Teal and New Zealand Scaup.
As our only endemic diving duck I think they deserve an indigenous name. While New Zealand Scaup is an accurate name as they are of the same genus as northern hemisphere scaup, to me teal are small dabbling ducks so Black Teal just seems wrong as a name.