PARASITIC WEAVE RBIRDS 5 



three regions." Sushkin's proposed classification of the family sup- 

 ports the contention that the Ploceidac originated in Southern Africa. 



Croolv (1958) concluded from beliavioral and structural data that 

 the Bubalornithinae, comprising the genera Bubalornis and Dinemellia, 

 should be considered of family status, allied to but separate from the 

 Ploceidae. He admitted that there were then no behavioral data on 

 Dinemellia comparable to those that he produced for Bubalornis, and 

 it would be surprising if the two prove very dissimilar basically. I 

 am still unconvinced that anything is to be gained by changing a 

 subfamily to a family of "insecure systematic status," especially as 

 the group is certainly a part of the weaver-bird complex. I prefer to 

 follow Sushkin, who considered Bubalornis as the oldest, most archaic 

 genus of the whole assemblage, and Plocepasser and its allies as among 

 the primitive "typical" weavers. The two subfamilies Bubalornithi- 

 nae and Plocepasserinae are confined to the open savanna country of 

 Africa, and may represent some of the oldest ploceid stock from which 

 diverged the Ploceinae, some of whose members spread to Asia. The 

 subfamily Passerinae seems also to have arisen in Africa, but managed 

 to spread to Europe and Asia. 



Compared to the Ploceinae, the Estrildinae are birds more gener- 

 ally of the savannas, not the forest. As Chapin suggested, the cooler 

 Palearctic climate may have barred their more northward dispersal 

 even though their favored type of terrain was more generally avail- 

 able there than it was for their sylvan relatives, the Ploceinae. This 

 conclusion seems justified inasmuch as the Estrildinae spread cast- 

 ward in tropical lands all the way to Australia. Among the genera 

 that did not spread beyond the African continent are the birds of 

 immediate interest to us, the viduincs. Judging from their habits 

 and especially from their preference for grass seeds in their diet, 

 Chapin concluded that "Hypochera, Vidua and their relatives have 

 always been savanna birds. Restricted as they are to Africa, on(> 

 may regard them as a special development of the southern savannas. 

 The distribution of the two species of Steganura [considered as one 

 species in this work], however, may be interpreted as shomng that 

 one of them early found its way to the northern savanna, though none 

 of the group reached India." 



Whether considered as the subfamily Viduinae or as a specialized 

 part of the Estrildinae, the viduines are certainly closely related to 

 the latter group. The similarity in the mouth markings of the nest- 

 lings of the species of Vidua and of their normal hosts of the genus 

 Estrilda and allied genera speak for close phylogenetic relationship 

 rather than for the results of adaptive evolution after the inception 

 of brood parasitism by the former on the latter. While Wolters 

 (1944, p. 29) saw little ph3dogenetic significance in these markings 



526526—60 2 



