2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



of Ann Arbor, Baton Rouge, Berkeley, Cambridge, Chicago, Los 

 Angeles, New Haven, New York, Philadelphia, Pittsburgh, and 

 Princeton, in the United States. To the officials of all these museums, 

 who have kindly sent me data or specimens, I hereby tender my thanks. 

 The following individuals also have helped with observational notes 

 and egg-specimen data: Salim A. AH, M. Courtenay-Latimer, G. 

 Duve, R. Kreuger, D. W. Lamm, R. Liversidge, G. R. Mountfort, 

 J. Ottow, C. R. S. Pitman, C. G. Sibley, C. J. Skead, G. Symons, 

 V. G. L. van Someren, J. G. Williams, and J. M. Winterbottom. 



My personal field experience with Clamutor, limited to the three 

 species that occur in Africa, continued to play a contributing role in 

 the present as in earlier studies. Acknowledgments, therefore, for 

 the support that made these field studies possible are due again to 

 the National Research Council, American Philosophical Society, the 

 Guggenheim Foundation, and the Smithsonian Institution. 



INTRODUCTION 



The genus Clamator is one of a number of genera of cuckoos which 

 are parasitic in their mode of reproduction. The vicissitudes of its 

 biological history which are reviewed in this paper are of interest in 

 clarifying some concepts involved in the overall problems of evolution 

 of habits in the puzzling family Cuculidae. 



Brood parasitism in the cuckoos is not a "single-line" development, 

 as it is in the cowbirds, the honeyguides, or the ducks, but comprises 

 many genera, some of which have evolved specialized features, such 

 as the evicting habit in the nestling stage. Other genera have de- 

 veloped elaborate egg morphism with related host-specific gentes, 

 some have an extremely restricted range of host species, others have 

 a broader choice of fosterers, while still others show none of these 

 refinements in their mode of reproduction. In the weaverbirds it is 

 known that the parasitic habit has arisen independently in two sections 

 of the family (Friedmann, 1960). Whether it arose equally inde- 

 pendently in different groups of genera of parasitic cuckoos is still 

 uncertain, but it has developed in various ways in the 18 genera that 

 are parasites in their mode of reproduction. 



These genera, each with its own special features and its own 

 peculiar problems, are of much interest to the student of adaptation 

 and evolution. C. D. Darlington (1953, pp. 441-443) wrote of the 

 European cuckoo, Cuculus canorus, that it was "... uniquely in- 

 structive in its relations with the environment. Exposed from hatch- 

 ing to an alien environment for innumerable generations, the be- 



