52 U.S. NATIONAL MUSEUM BULLETIN 22 3 



once a minute. It was tamer, less timid with respect to the human 

 observer, than was the young warbler with which it was reared. 

 Chapin (1954, p. 409) summarized the little that was recorded, as 

 follows: "For a while the fledglings are fed by their fosterers, then 

 thej^ begin to recognize their own kind and gather by dozens into 

 flocks with numbers of adults." Cheesman (in Cheesman and Sclater, 

 1936, p. 91) once saw an apparently unattended, lone fledgling near 

 Dangila, northwestern Ethiopia. 



Food and Feeding Hapits 



Adult: The adult birds are largely seed eaters. In the gizzards 

 of two specimens collected in Pemba, Pakenham (1939, p. 553) found 

 seeds of buUrushes. Mouritz (1915, p. 558) reported small seeds and 

 remains of insects in an example from Southern Rhodesia. In the 

 same country Irwin (1952, p. 115) describes the birds as feeding on the 

 ground. Chapin (1954, pp. 407-410) found nothing but seeds in the 

 stomach of a bird taken at Faradje, Belgian Congo. He writes that 

 as a rule this species clings to the stalks of grass and feeds on the seeds. 



Probably associated with its feeding habits is the peculiar structure 

 of the mouth of this bird. The sides of the mandibles are dilated 

 inward to the extent that they form two horny pads and leave only 

 a narrow medial groove between them in which the small tongue is 

 fitted. A similar medial groove accommodating the tongue occurs on 

 the palate, while on either side of the roof of the mouth, near the gape, 

 is a hard circular hollow into which the horny mandibular pads fit 

 when the bill is closed. The function seems to be to help crush hard 

 seeds used as food. Bannerman (1932, p. 254) sensed this function 

 when he commented that the "powerful biU must enable it to eat 

 some kind of hard seeds which are not available to other birds." 



Young: Pakenham (1939, p. 553) watched a pair of grass warblers 

 feeding two fledgling cuckoo finches some green caterpillars and grass- 

 hopper-like insects, and the gizzard of one of these young birds con- 

 tained the top of a small snail shell as well. Two fledglings taken by 

 Lynes near Alwanza, Tanganyika Territory, and now in the British 

 Museum, had bits of the shells of fairly big snails in their gizzards. 



Plumages and Molts 



Anomalospiza imberbis imberbis 



Adult male in fresh plumage: Forehead, lores and anterior part 

 of crown light Aniline Yellow (capitalized colors refer to the nomen- 

 clature of Ridgway, 1912). Rest of crown slightly darker and washed 

 with Light Grayish Olive, this color largely on tips and margins of 

 feathers. Hind neck and upper back more pronouncedly grayish 



