6 A NATURAL HISTORY OF THE DUCKS 



forms which combined the characters of the goose and duck tribe, the flamingoes, 

 the pelicans, cormorants, and their allies, the storks and herons, and the hawks, 

 once existed. The extinction of these primitive forms leaves us very much in the 

 dark as to their inter-relationships, but a few points have been brought out by the 

 discovery of fossils. 



In the Pleistocene and Recent deposits in Oregon are found many species which 

 still exist, besides a huge extinct goose, Anser condoni, and a gigantic swan. Fossil 

 swans have also been found in other parts of the world. The Pleistocene of New 

 Zealand has yielded a huge flightless, gooselike bird, Cnemiornis calcitrans, which 

 has several characters in common with the present-day Cape Barren Goose, and 

 has been placed in the same subfamily. It seems to have been exterminated quite 

 recently, perhaps at the same time as the Moa. 



Fossil geese belonging to the existing genus Anser have been found in the upper 

 Miocene and Pliocene strata in various parts of Europe. Chenornis, in the mid- 

 Miocene, is a fossil duck which is said to have affinities with other groups, possibly 

 the petrel, pelican, and tropic-bird families. There are many other fossil ducks of 

 existing or allied genera from Europe and the United States in Miocene and Pleisto- 

 cene, but curiously enough no fossil mergansers have been brought to light, which 

 may point to a recent origin for these fish-eaters. 



An entirely distinct family of anserine birds, the Gast-ornithidcp, have been dis- 

 covered in the Eocene of France and England. Gastornis, one of the genera in this 

 family, was a huge gooselike fowl as large as an ostrich, and even considered by some 

 as allied to the ostriches. One very peculiar thing about these huge birds was that 

 the sutures of the skull did not close with age, but remained open throughout life. 



In other strata there are fossils which show some affinity to anserine birds, but 

 the relationship is very vague. 



Considering the Anseres as a suborder, containing one family, Anatidce, the 

 swans, geese, and ducks, we must now ask how we are to divide them further, not 

 only for our own convenience, but in order to show as much as possible the closer 

 relationships. Almost any child can tell a swan, and few mistakes are possible either 

 with the true geese or the true ducks, but we have to consider subfamilies and genera 

 which merge into one another so gradually that a hard-and-fast line between geese 

 and ducks is impossible to draw. The skeletal characters are by no means as marked 

 as one would suppose, and so great an authority as Shufeldt has shown that the 

 skull of the Whistling Swan, apart from size, has no characters to distinguish it from 

 that of the Canada Goose. Indeed this goose is so much like a Mallard in the skull 

 form that osteologically no fixed line can be drawn. We have to take into account 

 the number of vertebrae, the general appearance and proportions, and even the 

 habits. 



The first subfamily of the Anatidce comprises the swans, or Cygnince, easily dis- 



