Proceedings of 

 the United States 

 National Museum 



SMITHSONIAN INSTITUTION • WASHINGTON, D.C. 



Volume 124 1967 Number 3633 



Alloxenia in Three Sympatric 

 African Species of Cuculus 



By Herbert Friedmann * 

 Research Associate, Department of Vertebrate Zoology 



In a recent note (1967) I have proposed the term "alloxenia" to 

 describe the situation wherein two or more related species of parasites 

 tend to use different species of hosts. Opposed to this is the term 

 "homoxenia," signifying the use of the same hosts by different species 

 of parasites. Just as geographical or ecological allopatry is of obvious 

 significance in the economy of related species with fairly similar 

 habits, so too the avoidance of needless or of difficulty-inducing 

 competition for brood hosts that is brought about by alloxenia confers 

 definite advantages on parasites with fairly similar needs. Given 

 sufficient time for development, alloxenia is, indeed, a situation that 

 one might expect to develop under the influence of natural selection. 

 The actual existence of alloxenia cannot be assumed, however, until 

 a considerable body of observational data is available for its 

 elucidation. 



The object of the present paper is to demonstrate that we have 

 now reached this point in our knowledge of the three largely sym- 

 patric species of Cuculus in Africa. As a matter of fact, I had antici- 

 pated this situation in my book on all the African parasitic cuckoos 

 (1949a, p. 190) when I wrote that they appear "to divide up both 



1 Director, Los Angeles County Museum of Natural History, Los Angeles, 

 Calif. 



1 



