356 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



lighter color and a white bill. In the third season the bill has be- 

 come jet black and about one- third of its plumage is still tipped 

 with gray; and until it is fully five years old an occasional feather 

 will present this tint." 



74. Olor buccinator (Ricn.). 

 TRUMPETER SWAN. 



Distr.: Chiefly interior of North America. In early days it 

 bred commonly, at least as far south as Dakota. At present its 

 nesting range appears to be from southern British Columbia north- 

 ward; winters on the Gulf coast of Louisiana and Texas and from 

 western British Columbia to southern California. In mild winters 

 a few may remain as far north as southern Illinois. 



Adult: General plumage, white; bare loral skin in front of eye, 

 not yellow; bill and feet, black; the distance from the front angle of the 

 eye to the back edge of the nostril is equal or less than the distance from the 

 back edge of the nostril to the end of the bill. 



Immature birds are ashy gray, often tinged with brownish on the 

 head and neck; bill and feet, dull yellowish brown, tinged with olive. 



Length, about 63; wing, 21 to 26; bill, about 4.50. 



The Trumpeter Swan occurs sparingly in Illinois and Wisconsin 

 during the migrations. It is fast becoming a very rare bird, at least 

 east of the Mississippi. 



