FOOTNOTE:
[1] The male and female of the northern diver (colymbus glacialis) resemble one another so much that it is very difficult to distinguish the one from the other. The immature bird has often been described by ornithologists as the female.
[1] The male and female of the northern diver (colymbus glacialis) resemble one another so much that it is very difficult to distinguish the one from the other. The immature bird has often been described by ornithologists as the female.