SCAUP DUCK 261 



Voice. Almost all sportsmen are familiar with the loud, hoarse note of the fe- 

 male Scaup, but very few indeed have heard the dove-like cooing call of the male. 

 Many observers have thought the male an absolutely silent bird; the explanation is 

 that this soft note carries only a short distance. The first and one of the best descrip- 

 tions that I can find is that of Faber (1822), but recent writers have generally failed 

 even to mention it. This note, which is primarily a courtship note, may sometimes 

 be heard at other seasons than spring, even in late autumn. I have heard it in No- 

 vember. It is best described as dove-like in quality, a short explosive cu-coo, the last 

 syllable strongly accented. At times it is practically inaudible and I feel certain it is 

 uttered more commonly than would appear to be the case. Both Audubon and Goss 

 (1891) evidenthy heard it. Allan Brooks likened it to the note of the Burrowing 

 Owl. 



The female has several notes, the usual one being a rattling kawp-kawp (Cor- 

 deaux, 1896) or perhaps better, a karr, karr, karr (Naumann, 1896-1905). Millais 

 (1913) heard a wounded male uttering a harsh note like the female's, but I have 

 never heard anything of the sort from the male. Other writers, like Seebohm (1885), 

 have spoken of the male's "loud, harsh scream," but I cannot help thinking that 

 these observers were mistaken as to the sex. It may be possible that young males 

 are able to make a noise resembling that of the female; on this point I am not en- 

 tirely satisfied. 



The trachea of the male is slightly swollen and flattened throughout its middle and 

 upper part, being smallest at the lower end. The labyrinth is left-sided, large and 

 flattened, its good-sized apertures covered with drum-like membrane. In general 

 structure it resembles the analogous organ in the Common Pochard, the Southern 

 Pochard and the Ring-necked Duck (see plate in Latham and Romsey, 1798, and 

 other more recent writers). 



Food. The ordinary food of this duck when on its winter quarters in salt-water 

 bays and estuaries is largely animal. It consists of great numbers of small shell-fish, 

 both univalve and bivalve, with vegetable matter, particularly the seeds of Zostera 

 and widgeon-grass (Ruppia). Minute crustaceans are also a favorite food. Fish ap- 

 pear to be rarely taken, although in captivity the Scaup feeds freely on salt-water 

 minnows (Fundulus) up to two or three inches in length. Scaups collected in Massa- 

 chusetts in January and February by the U.S. Biological Survey, contained only 

 about 3.17% of scallops, so that the damage to edible shell-fish on the New England 

 coast is probably negligible. 



In fresh water they feed freely on wild celery (Vallisneria) and pond-weeds 

 (Potamogeton), particularly the seeds. Their stomachs are usually well supplied with 

 broken-up shells and gravel, and pebbles up to half an inch in diameter have been 

 recorded. 



