Thus three subspecies of quail: the African ( Coturnix coturnix 

 africana ), the Japanese (C. c. japonicus ) and the European (C. £. 

 coturnix ) can be easily differentiated by their voices. Parus 

 atricapillus salicarius differs from P. a. rhenanus by its call. 

 Zonotrichia capensis ant illarum from San Domingo has a much louder song 

 than other subspecies. According to Pierce (19^8), the frequency of the 

 voice of Nemobius fasciatus fasciatus is 7, 500 cps, while in Nemobius 

 socivis it is 7,7UO and in N. f. tintulus 6,300 (1961). A good review of 

 the interspecific variability of birds' songs was written by Borrow (1961). 



The processes of sympatric and allopatric species formation, and 

 partial or complete overlapping of distribution areas, are clearly re- 

 flected in the voice. These processes produce cases in which the 

 voices in an area in contact with that of a closely related species or 

 subspecies differ more strongly than voices in areas having no contact. 



Thus in the group Bufo americanus (Blair, 1962), Bufo woodhousei 

 differs more markedly from the sympatric Bufo terrestris from Louisiana 

 and Georgia than from the allopatric Bufo terrestris from Florida. 

 Bufo woodhousei also differs to a greater extent from the sympatric 

 Bufo americanus from Oklahoma than from the allopatric Bufo americanus 

 from Wisconsin and Michigan. 



Microhyla olivacea and Microhyla carolinensis have different 

 voices in contiguous areas; but in more distant parts of their areas 

 have more similar voices (Blair, 1955)- Similar cases are described, 

 offering as examples the willow warbler, Palla's warbler, some Hyloc ichla 

 and others (Tembrock, 1959)- Of great interest are the data published 

 by Thoenen (1962). According to his investigations, Parus montanus 

 montanus is easily distinguished from P. m. salicarius in the Alpine 

 zone. But the Alpine P. montanus resembles the American P. atricapillus 

 and P. carolinensis in its song. There is greater resemblance between 

 P. m. salicarius and P. palustris than between P. m. montanus and P. m. 

 salicarius . The differences between the songs of P. m. montanus and P. 

 m. salicarius are so great that the birds do not "understand" each other 

 at times. 



All the above-mentioned demonstrate, without a doubt, that sound 

 mechanisms play an extremely important role in the processes of intra- 

 specific (populat ional ) and specific divergence, especially in the case 

 of birds. It has become clear that at present we underestimate the 

 importance of this role. Further development of investigations in this 

 direction will undoubtedly produce valuable new data concerning the 

 mechanisms of populational and specific isolation, and will serve to 

 broaden our concepts of the mechanisms of mi c roe volution. 



Local dialects, while reflecting and preserving the complex and 

 involved patterns of the specific population, also acquire traits of 

 complexity and of heterogenity. Some investigators (Thorpe, I96I; 

 Marler, 1956) make use of this fact in order to deny the functional 

 importance of local dialects. Marler (1956), for example, considers 

 them by-products of the imitative faculty of birds, and relates 



