Note:  Do not rely on this information. It is very old.

Canvasback Duck

Canvasback Duck (Fuligina vallisneria), a North American duck, highly esteemed for the table. The male is white with wavy black markings, head tinged with black, neck glossy chestnut, black pectoral belt. According to Nuttall, the principal food of these birds is not the freshwater plant which serves them for a specific name, but the marine grass-wrack (Zostera marina).