1913 1 Swarth: Geese of California 11 



A. O. U. Check-List (1910), namely, that there is one widely ranging 

 and exceedingly variable species, of which we can recognize four differ- 

 ent subspecies, canadensis, hutchinsi, occidentalis, and minima. The 

 material at hand illustrates every gradation of size, color, and pattern, 

 from typical canadensis on the one hand, through hutchinsi, to typical 

 minima at the opposite extreme. There is, however, a lack of material 

 indicative of intergradation between occidentalis and the other forms, 

 except as shown by the Prince "William Sound birds, which approach 

 minima in size, and by the type specimen of occidentalis which, as 

 previously pointed out, also inclines toward minima in certain of its 

 characters. It is highly probable that collecting in the proper regions 

 in summer would be productive of specimens variously intermediate 

 between occidentalis and canadensis, or between occidentalis and 

 minima. 



The presence in California during the winter months of thi-ee 

 subspecies of Bran/a canadensis, namely, canadensis, hutchinsi and 

 minima, occurring in large numbers in associated flocks, together with 

 the presence of a fairly large proportion of intermediates with diffi- 

 culty referred to any one form rather than another, is calculated to 

 produce an erroneous impression as to the distinctness and stability 

 of the various forms. It must be borne in mind that this is the winter 

 habitat of races which, except where our data is inadequate, are known 

 to occupy widely different areas during the summer months, and that 

 it is merely the similarity of their preferences and requirements which 

 brings the various races together in their common winter home. The 

 same may be said of Anscr albifrons gambeli, Chen hyperboreus, and 

 Chen rossi, these absolutely distinct species, together with the different 

 subspecies of Branta canadensis, all occurring during the winter 

 months in exactly the same localities in California. 



Birds taken upon their breeding grounds do not exhibit any such 

 diversity of characters as is illustrated in series of winter birds taken 

 at one locality. On the contrary, breeding birds from any one 

 locality are wonderfully uniform in all particulars. Much remains 

 to be learned in regard to the summer ranges of the North American 

 geese, but such exact data as is available serves to bear out the above 

 statement. 



There are, however, published accounts of high degree of authen- 

 ticity which are not clearly explicable, such as the alleged occurrence 

 of hutchinsi and minima over the same region, in part, during the 

 breeding season. It should be borne in mind, though, that the confu- 



