GOLDEN-EYE 317 



The eggs of the Golden-eye are laid on the rotten wood or other material at the 

 cavity bottom and down is added when the clutch is complete. Nests have been 

 found with well-incubated eggs that had no down. The clutch is very variable, all 

 the way from five or six to nineteen, with an average of around ten or twelve, but it 

 is very hard to determine the usual clutch because two or more birds often lay in one 

 nest. Brewster (1900) thinks that a nest which he found with nineteen eggs was the 

 work of one female. As many as forty eggs have been credited to one female (Plathe, 

 1904). That such large numbers are apparently laid in the artificial nest-boxes in 

 Finland does not seem improbable. The eggs are often packed solidly into the nest, 

 arranged in two layers or set in end-down, so that it is difficult to see how the female 

 can turn them. But turn them she must in some way or other or else they would not 

 hatch properly. The eggs are bluish green, which fades soon to grayish green, and 

 measure 59.19 by 42.55 mm. The greatest length is 67 mm. and the smallest is 52; 

 the greatest width is 45 mm. and the smallest width, 39.4 mm. (Jourdain, in Hartert, 

 1920a). If there are ten to twelve eggs their weight is actually greater than that of 

 the mother bird (Heinroth, 1922). 



The down is pale grayish, smaller than that of the Goosander or Shelldrake and it 

 is usual to see a tuft of this material sticking to the edge of the nest opening, which 

 gives one a clue to the inhabitants. 



The incubation period has not been satisfactorily defined. Blaauw's (1909) record 

 of twenty days under a hen is probably too short, and Heinroth's estimate of thirty 

 days, I should guess is somewhat too long. Naumann placed it at twenty-two days 

 and Mr. A. Wolfe of Edmonton {in litt.) hatched some under a domestic duck in 

 twenty-four days; under a bantam in twenty-eight days! This last seems to me the 

 most likely period. I have heard of one record of over thirty days but I am not cer- 

 tain of the reliability of the observer. Reliable data show that the closely related 

 Barrow's Golden-eye has a long period. 



There remains to be mentioned a very unusual trait in this duck: the apparently 

 tremendous competition which goes on around a favorite nest-hollow. It seems to be 

 unusual to find a female that is left entirely alone and four or five birds may have an 

 interest in one spot. Harper, who camped for several weeks close beside a nesting 

 female on Egg Lake, Athabasca delta, was able to make some interesting observa- 

 tions. He noticed, as others have, the remarkably abrupt manner in which females 

 enter the nest-hole, pausing a little outside to check their speed, but passing inside 

 with scarcely any hesitation. But the peculiar thing about this place was the num- 

 ber of other females who came to visit the nest, sometimes four or five birds circling 

 around it at one time and even fluttering before the opening while the rightful owner 

 was incubating. Even a female Buffle-head paid a visit to it. Brewster saw the same 

 sort of thing in Maine and concluded that more than one female took part in the in- 

 cubation. However this may be, it is interesting that on the evening of the same day 



