1918 ] Kennabd, Ferruginous Stains on Waterfowl. 12o 



flamingos are distinctly anseriform in this particular. Finally 

 it may be added that the study of the under tail-coverts has never 

 been undertaken and will probably give results as interesting and 

 suggestive as those afforded by the study of the major upper 

 coverts. 



FERRUGINOUS STAINS ON WATERFOWL. 



BY FREDERIC H. KENNARD. 



Several years ago at a meeting of the Nuttall Ornithological 

 Club at which I was present, there was an informal discussion among 

 some of the members, regarding the ferruginous suffusion that 

 occurs so frequently on the heads of certain geese, especially the 

 Snow Geese and Blue Geese. 



Some of those present seemed inclined to the belief that it might 

 be a phase of adult plumage, while others thought it merely a rusty 

 stain, such as occurs sometimes on the under parts of many of our 

 ducks. 



One eminent ornithologist then pertinently inquired, why, if it 

 were a stain, it should be so strictly confined, as a rule, to the fore- 

 head and cheeks, with swans as well as geese, and why also it should 

 occur in certain species of waterfowl, but not in others having 

 essentially the same habits and haunts. Another member wisely 

 suggested that a chemical analysis should be made of some of the 

 rusty feathers in question; but nothing further was done at that 

 time. ' 



Personally, I had, without giving much thought to the subject, 

 always supposed this to be a stain caused by extraneous matter 

 deposited in some way by the muddy water in which the birds fed. 



During the winter of 1916, my interest in this subject was again 

 awakened, while on a collecting trip after Blue Geese along the 

 Louisiana marshes bordering the Gulf of Mexico, and I have been 

 able, during the past year, to gather data from a number of muse- 

 ums and private collections, which included large series of skins 



