44 U.S. NATIONAL MUSEUM BULLETIN 223 



that he considered to belong to the cuckoo finch at Strathmore Ranch, 

 near Bulawayo, Southern Rhodesia. Aside from the fact that the 

 cuckoo finch does not have a nest and a readily collectable "set" of 

 eggs, Carlisle's specimens are too big (IS to 19.5 by 13 mm.) and are 

 marked with a few very sharp spots of dark umber or black on a 

 pale-blue shell color. 



All but one of the eggs found so far have been considerably larger 

 than those of the hosts with which they were associated, the Cisitcola 

 eggs varying from 14.5 to 15.5 by 10.5 to 11 mm. The one exception 

 was found in a nest of the striped grass warbler, Cisticola natalensis, 

 whose egg measured 2 mm. longer than did that of the parasite. 



That there are several records of two eggs or young of this parasite 

 in one nest indicates that either two females may lay in the same nest, 

 or that the same hen may lay more than one egg in the nest. We lack 

 data to determine which is true. In this connection, Pakenham (1939, 

 p. 553) in Pemba noted two young cuckoo finches in one "v^Ten grass 

 warbler's nest "of which one was almost ready to leave the nest, and 

 the other had sprouted quills, but not feathering generally. The 

 disparity in age of these two suggests different parentage. . , . 

 An alternative explanation, of course, would be that the layer of the 

 first Qgg laid again in the same nest after an interval of a few days." 



Aside from the mere appearance of the egg shell, and the fact that 

 two eggs may be laid in the same nest, we know nothing as yet of the 

 other important aspects of egg laying in the cuckoo finch. We still 

 need to discover the number of eggs laid in one season by one female, 

 the interval between them, theu' incubation period, whether each 

 hen shows any sign of host specificity in its choice of nests, and 

 whether it removes or punctures an egg of the host when depositing 

 one of its own. In one instance, described below under the striped 

 grass warbler, Cisticola natalensis, there was one broken egg of the 

 host together with a whole one of both the parasite and the host, but 

 there was no evidence as to the cause of the breakage. 



The meager data available do not permit any conclusions whether 

 the eggs of the cuckoo finch regularly show any similarity in colora- 

 tion with those of the host. The described eggs of the species of Cisti- 

 cola and Prinia victimized are sufficiently variable so that some of 

 them could approximate the descriptions of cuckoo finch eggs, but 

 in only one of the actual instances did the collector comment on 

 whether the eggs were notably similar or dissimilar. In this instance 

 the observer was impressed by the difference between the egg of the 

 parasite and that of the host (Cisticola natalensis), but this difference 

 was chiefly in size, and was not very great at that. 



Sich (1926) reported on cuckoo finches nesting in captivity. He 

 wrote that they not only nested and laid four eggs, but brought out 



