parasitic weaverbirds 51 



Nestling Stage 



The meager data available on the nestling stage indicate that 

 while usually only the young parasite survives to leave the nest, 

 sometimes the 3'oung of the host also survive. Cheesman (in Chees- 

 man and Sclater, 1935, pp. 615-619) noted that in nests of the brown 

 grass warbler, Cisticola brunnescens, in which he found young cuckoo 

 finches, no young of the host were present, and he inferred that the 

 parasites "seem to entirely dispose of eggs, or more probably the 

 young, whereas with larger species of Cisticola they were not always 

 successful in getting rid of them." In one nest of the larger rufous 

 gi'ass warbler, Cisticola galactotes, he found a fledgling warbler and 

 two young cuckoo finches, all ready to fly. Similarly A. Roberts 

 (1917, pp. 259-262) found a nest of the black-chested longtail, Prinia 

 Jlavicans, with a young longtail and a young cuckoo finch. In this 

 case the young parasite filled the whole of the bottom of the woven 

 nest, and at first sight the young warbler was not seen, as it was more 

 or less hidden by the larger parasite. 



The behavior of the newly hatched cuckoo finch toward other 

 young or eggs in the nest has not been observed. The duration of 

 the nestling stage is also still to be determined. The nestlings of 

 cuckoo finches are not known to have any mouth markings or papillae 

 as do the viduine parasites, but further definite information on this 

 point is urgently needed. 



A few writers intimated that the juvenal plumage of the cuckoo 

 finch is very similar to that of grass warblers of the genus Cisticola 

 that the cuckoo fmch parasitizes very intensively. While the degree 

 of similarity present may seem to be of possible advantage to the 

 cuckoo finch, this buffy, sparrow-like plumage is similar to what we 

 find in many species of ploceine weavers, and it need not be looked 

 upon as an adaptation acquired subsequently to parasitic breeding. 

 The lack of such similarity does not seem to impair the cuckoo finch's 

 success with Prinia hosts. For that matter, the frequently great 

 disparity between nestling plumages of parasites (e.g., cuckoos and 

 cowbirds) and of their numerous fosterere does not appear to be 

 a critical disadvantage for the parasites. 



Young Out of the Nest 



A number of naturalists have seen recently fledged cuckoo finches 

 being fed by their foster parents. These instances are described under 

 the pertinent host species. In the case observed by A. Roberts (1917, 

 pp. 259-262), the young parasite was attended by^ its fosterers for at 

 least a few days after leaving the nest. It kept up an incessant 

 demand for food and was fed by the longtails on an average of about 



