1918 ] Kennard, Ferruginous Stains on Waterfowl. 131 



Goose, and remains as a rule unstained. I have examined a few 

 Cackling Geese with cheeks slightly stained, but discolored speci- 

 mens of this species, as well as of the Hutchins' and Canada Geese, 

 are so uncommon as to be negligible. 



I have not attempted to gather any data regarding the other 

 members of the Branta group. The White-cheeked Goose, a bird 

 of the Pacific slope, has presumably habits similar to its cousin, 

 the Canada Goose, and but seldom acquires the stain, while the 

 Brant are salt-water birds. 



The dark feathers of the heads and necks of this group of birds 

 naturally do not show the stain as do those with the white heads; 

 but their cheeks should show it, if present, and their lower parts as 

 well. Such stains are, however, very exceptional, and the deduc- 

 tion seems reasonable, that their feeding habits cannot be the same. 

 According to a letter from Mr. McAtee, " the stomach contents bear 

 out this idea. Branta contains more largely things which may be 

 cropped and few root stocks; while Chen has more largely the 

 latter. On the whole also, Branta spends more time in the water 

 than Chen and feeds more on water plants, while Chen feeds more 

 on land, where not only digging, but often hard digging is required 

 to get the things it wants." 



As a summary of the above notes, and in answer to the questions 

 asked at the Nuttall Club meeting, it seems to be proven : 



First: That the ferruginous suffusion is caused in every case by 

 an extraneous deposit of oxide of iron (Fe203) on the outside of the 

 tips of the feathers; 



Second: The stain upon the heads of certain of our geese seems 

 undoubtedly to be brought about by their habit of digging for their 

 food among the mud and decayed vegetation in the iron-bearing 

 waters of the marshes and shallow sloughs, among which they feed 

 at certain seasons, particularly in places adjacent to the deltas of 

 the great muddy rivers; 



Third : Those species of the Branta group which remain unstained, 

 and inhabit essentially the same haunts as those of the Chen group 

 or the Emperor Geese, which become stained, do not have the same 

 feeding habits. They are apt either to frequent deeper waters 

 where they feed upon the grasses and aquatic plants, or else they 

 are found upon the drier fields and prairies in preference to shallow 



