LIFE HISTORIES OF NORTH AMERICAN WILD FOWL, 187 



got older, and in particular the brightness of the yellow of the head and the 

 depth of the black in front of the eyes slowly diminished, so that even when 

 a week old the delicate glory of it had largely disappeared. 



The young birds described above all died in the downy stage, but 

 another season he raised one young bird, in which he describes (1905) 

 the development of the plumage as follows: 



I am now able to give a complete account of the development of Ross's 

 goose, Chen rossi. This season my female laid three eggs, and, as in previous 

 years, she had proved to be a bad mother, I took the eggs away and put 

 them under a common hen. The period of incubation was 24 days this time, 

 and the eggs were hatched on the 10th of July. All the three eggs were 

 hatched, but unfortunately the heu in some way or other killed two of the 

 chicks the same day that they were born. The third escaped this fate and 

 was tenderly cared for by its foster mother. I have described ia detail tlie 

 color of the down in a previous letter (Ibis, 1903, p. 245), so that it will suffice 

 to say that the chick was a fluffy object with gray down and a bright canary- 

 yellow head. 



The little bird grew very rapidly, and when 2 weeks old was about the size 

 of a Japanese bantam hen. The bill was still black at this stage, with a pink 

 tip (the nail), and the legs were greenish. When 3 weeks old the feathers 

 began to appear on the shoulders, the flanks, the tail, and the wings. When 

 4 weeks old the bird was about the size of a small hen. The body was almost 

 entirely feathered, but the head and neck were still in down. The legs were 

 bluish and the bill was getting lighter in color. When 5 weeks old the whole 

 body was feathered, and when 6 weeks old even the flight feathers were of 

 their full length. The first plumage may be described as follows : General 

 color, white. A brownish-gray spot on the occiput, which runs down along the 

 back of the neck. The base of the neck and the mantle brownish gray, forming 

 a crescent of that color, of which the points are turned forward on each side 

 of the base of the neck. The smaller wing coverts are of the palest brownish 

 gray, with a dark spot at the tip of each feather. The flanks are gray, the 

 large flight feathers black. The first five secondaries have a dark spot in the 

 center ; those that follow are white, with only a very slight sprinkling of 

 brownish ; the three innermost have dark centers, and the white edges are finely 

 spotted with gray. The tail is white, with only a suspicion of a grayish tint 

 on the middle feathers. The legs are greenish gray with pink shining through. 

 The bill is pinkish, the lores are blackish gray, which color extends over and 

 behind the eyes. When 10 weeks old the bird began to faoU, and the gray 

 feathers of the juvenile dress were rapidly replaced by white ones. Also the 

 large tail feathers were molted, the central rectrices being dropped first. The 

 legs now began to turn pink in lamest, and the bill assumed its double colora- 

 tion of a greenish base and a pink tip. 



From the above account one would infer that the Koss goose ac- 

 quires its fully adult plumage at its first prenuptial molt, when 

 about 10 months old. As this molt probably involves the tail, all the 

 contour plumage, and the wing coverts, it would leave only the sec- 

 ondaries and tertials to be replaced at a complete postnuptial molt 

 the following summer. 



Winter. — The principal winter home of the Boss goose within our 

 limits seems to be in the central valleys of California, where it as- 

 sociates with the snow goose in the stubble fields and is often 



