212 BULLETIN 126, UNITED STATES NATIONAL MUSEUM. 



the following genera of water plants in the food of this duck: 

 VaUisneria, Lymnohium, Zizania, Piper, Elymus, Iris, Nwphar, Nym- 

 phaea, Ilyriophyllum, Callitriche, and Utricularia. 



During the winter on the seacoast its food consists of surface- 

 swimming crustaceans, crabs, starfish, and various mollusks; small 

 mussels, obtained by diving in the mussel beds, form the principal 

 [)art of its animal food at this season; but it also eats considerable 

 vegetable food, such as the buds and root-stocks of wild celery 

 {VaUisneria), and the seeds and succulent shoots of Zostera marina. 

 In the Chesapeake Bay region the scaup ducks feed on the roots of 

 the wild celery with the canvasbacks and redheads, where they are 

 quite as expert as any of the diving ducks in obtaining these succu- 

 lent roots; consequently they become very fat and their flesh, which 

 is ordinarily undesirable, acquires an excellent flavor. 



Mr. Arthur H. Norton (1909) found the stomach of a scaup duck, 

 killed on the coast of Maine in winter, filled with shells of Macoma 

 balthica. Dr. J. C. Phillips (1911) reported that the stomachs of 

 scaup ducks, killed on Wenham Lake, Massachusetts, in the fall, 

 ' ' held animal and vegetable matter in equal proportions, the items 

 being bur reed, pondweed, and bivalves {Gemma gemma)." 



Behavior. — Mr. Millais (1913) gives the best description of the 

 flight of this species that I have seen; I can not do better than to 

 quote his words, as follows: 



In flight they proceed at a rapid pace in a somewhat compact formation. The 

 birds fly very close together, and the sound produced hy their wings is somewhat 

 loud and rustling. On rising to fly the neck is straightened out, and the bird runs 

 along the surface of the water with considerable splashing for a few yards, but the 

 distance traveled on the surface of the water is coincidental with the amount of head 

 wind. In calm weather, if not much disturbed, they are always liable to take to 

 wing, and if the boat does not press them they will swim away for a long time before 

 turning around and facing up wind. When sitting on the sea, scaup often keep in 

 one long unbroken line parallel to the coast, and when rising the first bird at one 

 end takes wing and is followed in order right across the flock. When flying they 

 keep at a moderate elevation, but if the wind is offshore and they are desirous of 

 coming in to some estuary, they nearly always strike the sands or part of the coast 

 line which they desire to cross at exactly the same spot every day and at a consider- 

 able height. As they approach the waters of the estuary and feeding grounds the 

 leading birds then often make a dive downward, their movements being followed in 

 line by the rest of the flock, so that if the lino of birds is a long one it often has a 

 curious waving appearance. Doubtless this rising high as they approach the coast 

 line is dictated by common sense, for it is on the sands and rocky shore they are 

 most often shot at, and they learn caution from bitter experience. When on migra- 

 tion by day I have seen scaup circling at a great height, but when leaving the sea 

 or open water for the feeding grounds at night scaup as a rule do not fly much above 

 30 feet above the land or water. I have, when waiting for duck on the mussel beds 

 at dawn and sunset, occasionally obtained shots at flight at scaup, and the sound of 

 their rushing wings has often foretold their approach, when, if they could be seen in 

 time, I have occasionally made successful shots. When in small parties scaup may 

 sometimes be seen flying in oblique formation like other diicke, but when in large 



