I 



HOLBCELL'S GREBE 13 



while riding on her back. They soon learn to dive and to feed them- 

 selves on small fish, insects, aquatic worms, and vegetable matter. 



Plumages. The downy young show considerable variation in 

 color patterns, but in a general way they may be described as prac- 

 tically black above when first hatched, fading to blackish brown or 

 seal brown as the chick increases in size; this color includes the sides 

 and crissum, leaving only the belly pure white; the head and neck 

 are broadly and clearly striped, longitudinally, with black and 

 white; the chin and throat are often spotted with black but are some- 

 times clear white. There is usually a distinct white V on the top of 

 the head, starting on the forehead, above a superciliary black stripe 

 which usually includes the eyes, and terminating in broad white 

 stripes in the sides of the neck; there is also a median white stripe 

 or spot on the crown and the back is, more or less distinctly, marked 

 with four long stripes of dull white or grayish. The lighter stripes, 

 especially on the head and neck are often tinged with buffy pink. 

 This downy covering is worn until the young bird is more than 

 two-thirds grown, the colors becoming duller above and grayer 

 below. The first real plumage is acquired early in September, dark 

 above and white below, as in the adult, but signs of youth are re- 

 tained in the head and neck, both of which are more or less striped 

 with black and white on the sides; the neck is also more or less 

 rufous. I have a specimen in this plumage taken November 15, but 

 I have other specimens taken in November and December, appar- 

 ently young birds, which have lost all traces of the stripes and the 

 rufous neck. The stripes always disappear during the fall or early 

 winter, but the reddish neck is often retained until the young bird 

 acquires its first nuptial plumage. This closely resembles the adult 

 nuptial plumage but the colors are duller and not so pure; the chin 

 and throat are whiter, the red of the neck is mottled with dusky, the 

 crown is browner, fading gradually into the mottled cheeks; the 

 sharply defined color pattern of the head, so conspicuous in the 

 adult, is very much obscured in the young birds. At the first post- 

 nuptial molt, when the bird is a little more than a year old, I 

 think that old and young birds become indistinguishable, although 

 I am not sure that another year is not required to accomplish this. 

 The postnuptial or summer molt is complete and is prolonged 

 through August and September. The adult fall plumage is charac- 

 terized mainly by the absence of red which entirely disappears from 

 the neck and breast and is replaced by a white breast and a dusky 

 neck; the pale gray of the chin, throat, and cheeks is sharply defined 

 against the dusky neck, as it is against the red neck in the spring; 

 young birds have no such sharp line of demarcation; the crown is also 

 darker than in young birds. I have seen one specimen, No. 15994 



