Species identifies the type of waterfowl the down or feathers came from. Most commonly named is goose and duck which come from domesticated waterfowl.  Generally goose down is more expensive, but not always better.   Most regulations require that if an article is labeled as “Goose”, 90% of the material (down or feathers) must identify as goose. 

IDFL Test Summary - Species Analysis (EN,CN).pdf