LIFE HISTORIES OF NORTH AMERICAN WILD FOWL 181 



head and neck early in the winter, and by spring these have become 

 nearly all white in some birds, but there is generally more or less 

 black on the crown and hind neck. The bluish-gray feathers of the 

 adult plumage invade the lower neck and breast, much new plumage 

 comes in on the back, and new scapulars are partially or wholly 

 acquired. The tail is molted in the spring, beginning sometimes 

 as early as the last of February, but not the wings.. Before the birds 

 go north in the spring many of the first-year birds are practically 

 indistinguishable from adult birds except for the immature wings. 



What takes place during the following summer Ave can only guess 

 at, as summer specimens are lacking, but apparently a complete sum- 

 mer molt pi-oduces the second winter plumage, which is practically 

 adult. The head and neck become wholly white, or nearly so. The 

 wing is practically adult, with the pure gray lesser coverts and the pale 

 gray primary coverts ; the greater coverts have black centers, shading 

 off into silvery gray, and broad, white edges ; the scapulars and ter- 

 tials have the adult color pattern; and the primaries and seconda- 

 ries are deep black. The under parts are mainly bluish gray, and 

 the rump and upper tail cov^erts are clear pale gray. 



Subsequent molts produce similar plumages, and probably third- 

 year and older birds show greater perfection of plumage and more 

 brilliant color patterns. Many adult birds show more or less white 

 on the under parts, in strong contrast with the bluish gray, varying 

 from a small spot to a large area covering nearly all of the bell}^ ; 

 this may be the result of crossing with the snow goose or it may be 

 a character which develops and increases with age. Some observers 

 believe that the blue goose is a dark-color phase of the snow goose. 

 Mr. Blaauw, who has bred both species for some 22 years, has come 

 to this conclusion. On the other hand, Mr. Barnes, who has also 

 bred both, has come to the opposite conclusion; in addition to the 

 difference in the eggs and young, he says that the " build of the two 

 birds is very different, and their physical appearance is very dis- 

 tinct. The call notes are not very similar." It seems to me that they 

 are too unlike in many ways to be color phases of one species, and I 

 can find no conclusive evidence to prove that they are. They are 

 very closely related; so that, like the mallard and black duck, they 

 can interbreed and raise fertile hybrids, which they probably fre- 

 quently do. 



Food. — The feeding habits of the blue goose have been well de- 

 scribed by W. L. McAtee (1910), as follows: 



In the Mississippi Delta the blue geese rest by day on mud flats bordering 

 the Gulf. At the time of my visit (January 29 to February 4, 1910) these 

 were entirely destitute of vegetation, a condition to which the geese had 

 reduced them by their voracious feeding. Every summer these flats are cov-* 

 ered by a dense growth of "cut grass" (the local name for Zizaniopsis niili- 



