DOWN AND FEATHER QUALITY MYTHS
species of bird
While feather is common across bird species, down is unique to waterfowl. Within the waterfowl (ducks & geese) grouping, while geese are larger birds, there are some ducks that have large and more plentiful down clusters and even more expensive down (i.e. eider down). "Fill Power" is a better measure of quality than species.
color of bird
Waterfowl comes in many colors and sizes. The color of the bird alone is not a good indicator of quality of down nor feather. White geese and ducks are less prevalent than grey geese and ducks and desired more for white shell products driving pricing higher on those birds. In reality, that higher price is not reflective of better quality and grey birds can certainly have a higher Fill Power number and a better turbidity reading indicative of better quality feather and down.
origin of bird
It is a common marketing technique to call out the origin of the bird (i.e. "Siberian Goose Down") to conjure images of warmth and make products sound more desirable. In reality, the origin of the bird means little and the Fill Power and Turbidity are the more important measures of warmth. In fact, some of the largest clusters of down can be found on Chinese geese/duck that have aged to maturity vs. younger European geese/duck species