NO. 4 AVIAN GENUS CLAMATOR — FRIEDMANN 29 



Clamator glandarius extended its breeding range into sub-Saharan 

 Africa, the ecological shift was one that involved a marked change 

 in host choice, even a virtual repudiation of a previously highly 

 evolved egg adaptation, but, as it did not involve any apparent, drastic 

 alteration in the daily life or feeding habits of the adult cuckoo, no 

 comparable evolutionary change transpired. 



It follows from this that, whereas in the case of self-breeding birds 

 the entire biology of the species is a closely coordinated unit (almost 

 what in current commercial jargon is referred to as a "package 

 deal") on which selection may operate, in the case of brood parasites 

 there is cleavage resulting in two fairly separate parts. The evolu- 

 tionary climate ambient to the egg and nestling stages is that of the 

 host species and has relatively minor connections with, and repercus- 

 sions upon, the selective factors surrounding the life of the adult 

 parasite. This may have helped make it possible for Clamator 

 glandarius to invade vast new areas and to remain unchanged. Con- 

 currently, it must be assumed that the new, non-egg-adapted hosts, 

 suddently parasitized by the newcomer, had no previous need to 

 evolve any particular acuity of discrimination and thus were rela- 

 tively easily susceptible to parasitism. 



As far as casual observations go (and these are all that have been 

 recorded in the literature), the great-spotted cuckoo seems equally 

 successful in the various portions of its range. It might be expected 

 that the wide discrepancy in the degree of host adaptation it shows 

 in tropical and southern Africa on the one hand, and in the Mediter- 

 ranean area on the other, would be reflected in its local numerical 

 status, but the available evidence does not point to any such effect. 

 It must be admitted, however, that the data are still very superficial 

 and imperfect. If anything, the fact that unusually large numbers of 

 its eggs are often found in single nests of its corvine hosts in the 

 areas where the cuckoo is nonadapted might even suggest a relatively 

 greater abundance of the parasite in proportion to the available host 

 population there. 



The known hosts of the great-spotted cuckoo, as listed here, are 

 primarily birds of two families, the Corvidae (crows, jays, magpies, 

 and piapiacs) and the Stumidae (starlings). The other three in- 

 cluded species are a kestrel, which was probably an "unintended" host 

 choice as the bird was using an old magpie nest, and two South 

 African ground-tunnel nesters, the hoopoe and the ground wood- 

 pecker, which may have been "acceptable" to the parasite because of 



