82 PATAGONIAN EXPEDITIONS I ZOOLOGY. 



that the secondaries have a whitish appearance. This varies in individuals 

 and does not seem to be correlated with age or season. 



Lower parts : Silky white with some dusky mottling. The flanks and 

 sides dark brown approaching the back in color but more ashy and 

 mottled with rufous in a varying degree. 



Iris dark hazel, with a narrow outer rim of yellowish white. 



Bill pale, almost white with a slight greenish tint and having a distinct 

 well defined black band across both mandibles. 



Tarsi and feet greenish slate color; the greenish shading is not so 

 apparent on the inner surface of the toes or tarsi. 



Adult in Non-breeding or Winter Plumage. The appearance of this 

 grebe in this phase of plumage differs from that described as follows : The 

 chin and throat are white generally strongly suffused with rusty. This 

 suffusion is very pronounced on the fore neck, sides and flanks, and is 

 noticeable on the upper parts generally. The belly is less affected in 

 this way than the other parts. 



Young of the Year. Young birds of the year resemble winter adult 

 birds, but may be readily recognized by dark brown longitudinal markings 

 on the sides of the face and throat. The bill is as long as in adults but 

 is noticeably more compressed. 



Young in Down. Young in the downy phase are of a general dusky 

 brown coloring, striped longitudinally with white. The head and neck 

 are very definitely marked in black and white striping. There is a chest- 

 nut area in the middle of the crown, and two chestnut bands across the 

 nape. The chin, throat, breast and belly are white and the sides and 

 flanks greyish brown. 



Geographical Range. Patagonia, the Argentine Republic, and north- 

 ward throughout South America, the West Indies, Mexico and North 

 America as far north as Hudson's Bay and the Great Slave Lake. The 

 Bermudas. Breeding locally throughout its range, and being migratory 

 in North America and probably in South America, in the regions where 

 ice is formed during the colder portions of the year. 







The Princeton University Expeditions did not observe or secure this 

 species in Patagonia, though it doubtless occurs in at least the northern 



