■5^6 SxODGRAss, Food and Size of Bill in Gcosptza. Loct' 



and each of these had only seed No. 4 in its stomach. The 

 specimens were collected in February. 



Seventeen specimens were examined from Iguana Cove at the 

 southern end of Albemarle, separated from Tagus Cove by a dis- 

 tance of about fifty miles. Here seed No. i was eaten by one 

 bird, No. 2 by one bird, No. 4 by one bird, No. 15 by thirteen 

 birds, No. 44 by three birds, and No. 55 by one bird. Thus, the 

 only seed fed on at all constantly by the Iguana Cove birds is seed 

 No. 15 — a seed found in only one stomach at Tagus Cove. The 

 Iguana Cove specimens were collected in December. 



Since we do not know what species of plants the different seeds 

 belong to, we cannot say whether the differences in the food of the 

 birds at Tagus Cove and Iguana Cove is due to a difference in the 

 floras of the two localities, to a difference in the time of ripening 

 of the seeds, or to a difference in the preferences of the birds with 

 regard to the seeds at the two places. Since, however, seed No. 

 15 was found in abundance in the stomachs of birds taken on 

 James, Seymour, Duncan and Barrington Islands in April and 

 May, it would appear that the seeds should be ripe at Tagus Cove 

 in January if they are ripe at Iguana Cove in December. That 

 the plant occurs at Tagus Cove is shown by the fact that the seeds 

 were found here in one stomach. The entire diet of the Tagus 

 Cove birds consisted of seeds Nos. i, 2, 4, 6, 8, 15, 22, 24, 41, 58 

 and 59 ; that of the Iguana Cove birds of seeds Nos. i, 2, 4, 15, 

 44 and 55. Of the thirteen kinds of seeds only four are common 

 to both sets. Hence, there is most evidently a difference in the 

 food of the individuals at the two places, at approximately the 

 same time of the year. It is, perhaps, most probable that this 

 difference is due to the same seeds not being available in the same 

 relative numbers at the two places. 



Of five specimens from Narborough Island, taken in December, 

 three had in their stomachs only seed No. 8, the other two con- 

 tained only seed No. 22. These thus fed on the principal part 

 of the diet of the Tagus Cove birds. 



On James, Seymour, Duncan and Barrington Islands Geospiza 

 fuliginosa parviila feeds almost exclusively on seeds Nos. 14 and 

 15. Specimens of one or both of these seeds were found in the 

 stomachs of all the thirty-six birds examined, except in one from 



