2^4 BULLETIN 121, UNITED STATES NATIONAL MUSEUM. 



tion of the immature plumage to be shed; in a molt which is normal, the two 

 raitldle rectrices, which are the longest of the twelve, being the final ones to go. 



I have examined a large number of young gannets in first and second 

 year plumages (I have a series of 26 immature birds in my own col- 

 lection), all of which agree substantially Avith Mr. Gurney's observa- 

 tions. During the first year young gannets are extensively mottled 

 on the under parts, with an increasing amount of white in heads, 

 necks, and under parts toward spring; the upper parts are slate 

 colored with a hastate spot of white at the tip of each feather. These 

 slate-colored feathers with the white spots are characteristic of the 

 first-year plumage; but they are renewed on the back, rump, and 

 lesser wing coverts at the first complete molt, when the bird is about 

 a year old, so that they appear also during the first part of the second 

 year; however, the white tips disappear by wear during the fall, and 

 before winter the young bird has a solid black back, A feAV white 

 feathers appear in the lesser wing coverts at about this time. 



During the second winter, then, the young gannet has a solid 

 black back in which an increasing number of white feathers appear 

 toward spring, showing first in lesser wing-coverts, then in the 

 scapulars, and lastly in the back. The head, neck, and under parts, 

 which are largely white in the fall, become increasingly white during 

 the winter and spring; and the yellowish suffusion comes in on the 

 head. The secondaries are still all black and the tail feathers all 

 dusky. By the next summer, when the young bird is two years old, 

 the back and wing coverts are about half white and half black, in 

 a variegated pattern of wdiolly white and wholly black feathers. 

 Many birds in this plumage are seen in the breeding colonies and are 

 probably breeding. 



At the following molt, which begins as early as June, when the 

 bird is two years old, white feathers begin to appear in the second- 

 aries and in the tail, the wdiite feathers in the upper parts increase 

 and the black feathers decrease until the bird is three years old. The 

 summer and fall molt, at this age, probably produces the fully adult 

 plumage in many individuals; but in many cases, perhaps in all, 

 traces of immaturity, such as black secondaries, alternating or scat- 

 tering through the wings, and black central tail feathers, persist 

 through part of all of the fourth year. 



I have seen birds which I call 40 months old in this plumage, but, 

 as late winter and early spring specimens are lacking, I can not say 

 whether these last black feathers are shed before the bird is four 

 years old or not. Certainly at the four-year old molt, if not before 

 that, the plumage becomes adult. During all of this time the young 

 bird has been undergoing an almost continuous molt, represented by 

 two semi-annual molts, much prolonged during the earlier years so 

 that they nearly overlap, but later becoming restricted to a postnup- 



