304 SNODGRASS AND HELLER 



Along with the moulting of the feather there takes place a gradual 

 change in the color of the feathers. The plumage becomes darker 

 through the successive sets of feathers having not only more dark color 

 but also a duskier shade of dai-k color and narrower pale edgings. 

 In the male the color change is from light brown, through dark dusky 

 brown to black ; in the female from light brown to dark brown. The 

 spreading of the dark color is due in part also to the wearing away of 

 the light margins of the feathers, so that general color of plumage 

 formed of old feathers is darker than that composed of new feathers. 

 Hence, both males and females moult slowly and gradually from 

 December into February, the new feathers having successively 77iore 

 dark color on them, and the dark color becoming successively darker^ 

 being always brown in the females but changing in the males from 

 light brown, through dark and dusky-brown, to black. 



Young birds taken at Tagus Cove in June are in Stage II. One 

 male taken June 9 is in Stage V and is not moulting. We have no 

 other specimens from Albemarle taken after the bi^eeding season. 

 Hence we do not know what phases of plumage the birds are in on 

 Albemarle during the time from March till December. Birds taken 

 on the other islands, however, during April, May and June are mostly 

 either in Stage VI or in Stage II. We have twenty two males from 

 Indefatigable and Seymour taken during the last of April and the first 

 of May that are in Stage VI. One is in Stage V and has a few new 

 feathers growing in on the breast. Several others are in Stages IV 

 and III and most of these are moulting. Besides these there are 

 numerous specimens in Stage II, birds just from the nest. From 

 Charles we have two adult males in Stage VI, five adult females, and 

 numerous young birds in Stage II. We have no material to indicate 

 when the transition from Stage II to Stage III takes place. Nor do 

 we know at what age adult males in Stage VI change from the black- 

 ish-brown phase to the purely black phase. The fact that many 

 breeding males possess the blackish-brown plumage would indicate 

 that the purely black plumage is not acquired until during the second 

 year. 



Habits^ Song^ Nests and Eggs. — Geospiza fiili'giftosa parvula 

 is extremely abundant about Tagus Cove on Albemarle, living 

 everywhere in the dry brush that covers the walls of the old tufa 

 craters of this part of the island. The individuals commonly asso- 

 ciate with one another in small flocks and often mix gregariously 

 with the less abundant, larger-billed Geospiza fort is. Although their 

 food consists almost entirely of seeds, yet many of the birds may 



