30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



their general similarity to the nesting tunnels of the pied starling, 

 Spreo bicolor, a favored and frequent host there. 



The predominant role played by members of the Corvidae as 

 fosterers of this cuckoo is indicated by the fact that of a total of 172 

 nests parasitized, 141 were of various corvids; 89 nests belonged to 

 crows of 6 species (Corvus cor ax, cor one, ruficollis, albus, rhipidurus, 

 and capensis) ; 1 was of a raven, Corvultur albicollis, 48 were of 2 

 species of magpies (Pica pica and Cyanopica cyanus), 1 was of a 

 piapiac (PHlostomus afer), and 2 were of a species of jay (Garrulus 

 glandarius). Of the remaining 31 parasitized nests, 28 belonged to 7 

 species of starlings. Of these 14 were of the pied starling, Spreo 

 bicolor; 5 of the red-winged starling, Onychognathus morio; 4 of the 

 glossy starling, Lamprotornis nit ens; while of the other species single 

 instances only have been reported so far. 



Falco tinnunculus tinnunculus Pica pica bactriana 



(in an old Pica nest) Pica pica galliae 



Upupa epops africana pica pica melanotos 



Geocolaptes olivaceus pjca pica mauritanica 



Corvus corone sardonius Garrulus glandarius krynicki 



Corvus corone corone Ptilostomus afer 



Corvus ruficollis edithae Acridotheres tristis tristis 

 Corvus corax corax 



Onychognathus morio morio 

 Spreo bicolor 



Corvus albus 



Corvus capensis capensis ^ 



Corvus capensis kordofanicus ^preo albicapillus 



Corvus rhipidurus Lamprotornis nitens phoemcopterus 



Corvultur albicollis Lamprotornis caudatus 



Cyanopica cyanus cooki Lamprotornis chalybeus cyaniventris 



Pica pica pica Lamprotornis chalybeus sycobius 



As we have seen in the case of Clamator jacobinus, in the present 

 species also, it is the sub-Saharan segment of its total membership 

 that is the less well adapted in its egg coloration. However, in both 

 these species, the available observational evidence gives no grounds 

 for assuming that the sub-Saharan birds are less "successful" than 

 their more completely and more perfectly adapted northern segments, 

 insofar as "success" may be implied from ability to survive in num- 

 bers over a vast area. 



We cannot, however, deduce from this that adaptation has lost its 

 value and significance in one geographic portion of the total distribu- 

 tional range of this one genus of birds, while remaining advantageous 

 elsewhere in the same genus, as well as in most of the rest of the 

 animal kingdom. Certainly the case for the natural selective value 

 of adaptation generally is so strong, so well-nigh invariable, that we 



