6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 45 



might go through what seemed Hke playing at nest building or play- 

 ing at heterosexual pursuit, the young parasitic widowbirds were 

 interested in watching the breeding preparations of their fosterers. 

 The precise observations they made and the degree to which they 

 seemed to incorporate these impressions were thought to become im- 

 portant later in their lives in helping to synchronize their reproduc- 

 tive cycles and activities with those of their hosts, and so to be- 

 come significant in the breeding success of the widowbirds. 



Inasmuch as Nicolai's work has not yet been published with suffi- 

 ciently detailed documentation, it is somewhat difficult to appraise 

 and to criticize his conclusions. The following comments must be 

 read with this in mind, and some doubts that are raised here may prove 

 to l)e baseless. I must stress that the observations, surprising as 

 they seem to me, merit serious and respectful consideration. Their 

 interpretation seems to be less certain. 



For one thing, in a state of captivity birds may sometimes do 

 things they would have little chance of doing or, as far as we know, 

 do not do, in a wild state. I do not know whether Nicolai's birds 

 had the presumed fosterers with them in the cage or in nearby cages 

 where they could hear them. If they were not actually raised in 

 captivity by these fosterers, one wonders how Nicolai could know 

 which was the foster parent species in each instance, unless he as- 

 sumed the most likely one from the total recorded literature (as 

 was brought together in my book), or unless he assumed the iden- 

 tity of the host from the vocabulary of the parasite. The latter 

 would be a matter of circular reasoning which would hardly be con- 

 vincing, and which I cannot believe was done. Yet this was the way 

 in which some of Neunzig's original (1929) conclusions seem to have 

 been achieved. 



I am wholly convinced that it is possible to learn many things, 

 including vocalizations, from captive birds that it would be verj' 

 difficult to learn in the free state, but I am still surprised that no 

 one ever reported any constant and marked specific differences in 

 the notes of the various species of Vidua in Africa. Although my 

 own fieldwork is now many years past, and I do not pretend to re- 

 member accurately the songs and calls of these birds, I can find no 

 mention in my journals of any marked differences between them, 

 and I have found no published observations of others to this effect. 

 This suggests that the differences noted in aviary birds are not suffi- 

 ciently striking to be obvious in the field but require close-up ob- 

 servation for their discrimination. As a matter of fact, the vocali- 



