137 



feathers being interspersed through the black. The white nail on the 

 bill is generally crossed by one or more longitudinal stripes of dark 

 horn color. In spring, as the breeding season approaches, the bill 

 becomes a clear waxy yellow. There is also much variation in size 

 among adults of this species. I have examined a number of speci- 

 mens which by dii'ect comparison were at least one-fourth smaller than 

 the average. 



256. A. cserulescens Linn. Blue Goose. Although less abun- 

 dant than the preceding species, it is far from uncommon. Many are 

 sent to the Chicago market with the preceding during the migrations. 

 During some seasons the blue geese are nearly as numerous as the 

 white-fronted. Its habits and migrations, while with us, are essen- 

 tially the same as those of the preceding species. The adults of tliis 

 species invariably possess the white head and upper part of the neck, 

 which in the younger specimens is more or less variegated with dark 

 feathers. These disappear as the bird becomes older, and in many the 

 head is a pure snowy white, in shai-p contrast to the dark plumage of 

 the rest of the upper parts. The young would appear, at first sight, 

 to be a distinct species, so different is the pattern of coloration. The 

 white of the head, neck, abdomen and tail coverts is entirely absent, 

 and the bird is of au almost uniform ashy plumbeous, slightly darker 

 about the head and lighter on the abdomen. This plumage is retained 

 until the second year, at least, as many specimens are procured iu 

 spring with the dark head, neck and abdomen still immaculate, and 

 these, I think, are young of the preceding year. At the same time 

 specimens are found with the dark feathers about the head well mixed 

 with white, representing the second year. In birds of the third year 

 the white predominates, but not until the fourth or fifth year does the 

 plumage become perfect. 



257. A. hyperboreus var. hyperboreus Pall. Sxow Goose. 

 257a. Var. albatus Cass. Lesser Snow Goose. Both forms are 



found throughout the state, during the migrations, and, although Mr. 

 Eidgway gives the albatus as the more common form, I think they 

 occur iu about equal numbers. The adult plumage of this species, as 

 is well known, is pure white, with the primaries tipped with jet black. 

 The young are quite different. The crown, back of neck and fore part of 

 shoulders are dark plumbeous ; the tip of each feather being whitish 

 produces a grizzled appearance. A dark line extends from the eye to 

 the upper angle of the bill. The frontal region, cheeks, throat, fore 

 part of neck, breast, sides of body and rump are soiled ash}^ lighter 

 than the back of the head and neck, and appearing much as though 

 caused by the continued contact of white feathers with dark earth ; 

 but a close examination shows that the effect is produced by each 

 feather being mottled with tine dusky spots, which ou the sides nearly 



ESSEX INST. BULLETIN. VIU 11 



