SCAUP DUCK 265 



necked Duck. The average measurements of one hundred eggs mentioned by Hartert 

 (1920a) were 61.94 by 43.65 mm. Riemschneider (1896), who says he measured far 

 more than one hundred, gives the average as 63 by 43 mm. The maximum length and 

 breadth given by Hartert are 68.1 and 48 mm., the minimum 54.5 and 40.7 mm., 

 respectively. Riemschneider mentions an abnormally small egg measuring only 

 46 by 34 mm. The nest-down is as large as that of the Mallard, dark brown to black- 

 ish, without pale tips, but with inconspicuous white or brownish-white centers (See. 

 bohm, 1896; A. C. Jackson, 1918). 



There are very few notes as to the length of the incubation period. Hantzsch 

 (1905) considers it "about four weeks," but Mr. A. Wolfe of Edmonton, Alberta, 

 writes me that he has hatched Scaup eggs under a hen in twenty-two to twenty- 

 three days. In fact nearly all the diving-duck eggs which he has handled hatched in 

 from twenty-one to twenty-four days. If artificial heat was used they hatched even 

 sooner than under hens. I must confess that the shortness of this period was at first 

 very surprising to me and I was unable to explain it. Later, however, I got some ac- 

 curate data from Mr. Wormald which points to a short period, for rather stale eggs 

 which he got from Iceland came out in from twenty-five to twenty-seven days and 

 they would certainly take longer than fresh eggs under natural conditions. 



Some interesting accounts of the behavior of the parent birds during and after 

 incubation may be found in the literature. Like other ducks the female Scaup covers 

 the eggs when she voluntarily leaves the nest. This is done by a few rapid move- 

 ments, after which she runs a few paces toward the water in a stooping attitude; 

 raising the head and neck and taking a good look around, she appears satisfied and 

 waddles slowly to the water (Millais, 1913). Kriiper (1857) and Riemschneider 

 (1896) assert that when frightened from the nest the female always soils the eggs 

 in Eider-duck fashion! 



Although at first the males remain in the vicinity of the nest, they flock together 

 after incubation has commenced. Hantzsch (1905) thinks that even after flocking 

 they sometimes rejoin the female at night and he even thinks that the sexes are 

 loosely associated after the young are hatched. The Pearsons (1895) also state that 

 they have seen the male with the family in a few instances. Such cases are, however, 

 exceptional and one can never tell whether the male is really the mate of the female 

 in question. Millais (1913) particularly remarks that he never saw any male come 

 near the female after she had hatched her young. He adds that there were a few 

 males, doubtless the husbands of sitting ducks, on the river below his camp (Ice- 

 land) but they never took the smallest notice of any females with young that came 

 near them. 



There seems to be a tendency for the various families to pack together, as Eiders 

 and Mergansers do. In Alaska Nelson (1887) noted that in some ponds six or eight 

 families were united. The young grow quickly and are on the wing in five or six 



