NO. 3 THE PROBLEM OF THE VIDUINAE — FRIEDMANN 5 



markings of the nestlings are also valid morphological characters in 

 themselves. The fact that these buccal patterns may be functional as 

 well as morphological, and hence to some extent possibly subject to 

 the pressure of natural selection, need not rule out the possibility, 

 the probability even, that they are also phylogenetically stable charac- 

 ters, useful as indicators of relationship. This idea is by no means 

 novel at this point, nor was it in my i960 discussion, where (p. 24) 

 I pointed out that Morris (1957, p. 199) concluded that these mouth 

 markings were conservative taxonomic characters and as such were 

 useful aids to understanding the evolution of the birds that have 

 them. 



Nicolai (1961) has recently published in abbreviated form the re- 

 sults of a study of the vocalization of several species of Vidua 

 under aviary conditions. He studied with a tape recording the sounds 

 produced by V. macroura, V. regia, V. chalyheata, and Steganura 

 paradisaea and reported that part of the notes of each was a fairly 

 accurate copy of the song of their host species. He stated that the 

 viduine sounds comprised a "weaverbird-like" series of notes, scarcely 

 distinguishable in the four species, and a series of loud notes and 

 songs of the respective host species (various species and races of 

 Estrilda). Nicolai found in the ploceids and estrildids closest to the 

 viduines all songs and notes to be consistently innate and nonvaria- 

 ble, and he concluded that probably the notes of the viduines were 

 similarly somewhat "fixed." He went on to speculate that the young 

 A'^iduinae probably acquired their vocabulary from their foster parents 

 during their period of dependency in and out of the nest. Only in 

 this way did he think the exclusive reproduction of the vocabulary 

 of the particular host species could have been made possible. Fur- 

 thermore, he pointed out that in the case of V. macroura, which Is 

 known to parasitize a number of species of Estrilda, each male had 

 invariably only the notes of one host species. There were no cases 

 of mixed songs, a fact which he considered in agreement with his 

 premise as to how the imitative process could have taken place. On 

 the other hand, Nicolai further contended that the "whispering nest 

 notes" of the male, which appear in the vocalization of V. regia 

 and V. chalyheata, were learned somewhat later, after the birds had 

 become self-sufficient and no longer were in constant contact with 

 their fosterers, when the latter began preparing to breed again and 

 began nest building anew. 



Nicolai further concluded that whereas, at the close of the period 

 of parental dependency, the young of other, self -breeding, passerines 



