NO. 3 THE PROBLEM OF THE VIDUINAE — FRIEDMANN 3 



tially similar to their estrildine hosts, ". . . auf Grund wirklicher 

 Verwandtschaft . . . ," and he considers the Viduinae as the sec- 

 tion of Ploceidae nearest to the Estrildidae. 



The iinmediate problem of uppennost concern to me was, and still 

 is, how to interpret most cautiously and most accurately the parasitic 

 breeding habit of the viduines, and it was obvious that to do so 

 entailed an appreciation of the degree of their phylogenetic affinity 

 to their chief hosts, the waxbills forming the estrildine group. 



If the two groups, Viduinae and Estrildinae, were considered as 

 closely related and as stemming from a common ancestral stock, the 

 striking similarity in the mouth markings and reflection globules of 

 their nestlings could be interpreted readily as something retained by 

 both from the stock from which the two groups bifurcated. If, how- 

 ever, the two groups were looked upon as not so closely related 

 and as not derived from a common ancestry, this important feature 

 of their young would have to be treated as a parallel development, 

 and quite probably as an adaptive one on the part of the parasitic 

 Viduinae. This is, in fact, what Steiner concludes when he writes 

 (translation mine) that "in the viduines, as a specialized small sub- 

 family of the ploceines, we have notliing else but a case of true 

 mimicry, which, in the imitation of the mouth markings, is not more 

 astonishing than are other known examples in insects, snakes, and 

 other creatures, and which have developed in the viduines in place 

 of the complicated reflex behavior of nestlings of other brood para- 

 sites . . . ," such as the evicting behavior of young cuckoos of some 

 species, and the deliberate and usually lethal attacks by newly hatched 

 Indicators on their nest mates. Steiner expressly calls the mouth 

 markings a "spermestid character" in the viduines, and he considers 

 that in any evaluation of them a decisive role would have to be as- 

 signed to the thought that the viduines obtained or developed 

 "through true relationship, in their 6 or 7 species, various distinct 

 mouth-markings similar to those of their similarly distinguishable 

 host species — Pytilias, Granatinas, Lagonostictas, and Estrildas. This 

 would presume that each of their species had developed with its co- 

 ordinated host species from a primitive form, which, in retrospect, 

 must be assumed to have had a disclosed value for each presumed 

 parasite-host pair of species." As I pointed out in my account, this 

 point of view has also been stated by Southern (1954), who accepted 

 the opinion that the viduines were extremely specialized brood para- 

 sites, each species being practically an obligate parasite of a single 

 species of estrildine host to which it was thought to be permanently 



