68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



its Juvenal plumage has the remiges extensively reddish, suggesting a 

 relationship with C. coromandus. Aside from this, there is only one 

 point worth mentioning in any detail, the possible geographic variation 

 in the adult C. glandarius. 



Clancey (1951, p. 141) separated the population breeding in Africa 

 south of the Sahara from the nominate, Mediterranean basin birds, 

 and gave them the name choragium. The characters of this southern 

 race were smaller size and warmer buff on the throat and breast with 

 less pronounced dark shaft streaks on the feathers. Judging by 

 Clancey's account, Gilliard examined for him the material, totaling 

 101 specimens, in the American Museum of Natural History and 

 apparently agreed in considering the two populations as distinguish- 

 able. In the course of my studies I have examined nearly 200 addi- 

 tional examples, including 177 in the British Museum, and I found 

 that there was very extensive overlapping in all these characters. The 

 buff tone of the throat and breast in fully adult birds may average 

 very slightly warmer in choragium, but great care must be taken to 

 compare birds of the same age, as the young of both populations are 

 warm tawny buff on the throat and breast and adults of both largely 

 lack this color and are not more than pale buffy cream with a slight 

 ashy tinge. I could not find any constant difference in the development 

 of dusky shafts on the feathers of this area in the two groups of 

 birds. Furthermore, the size characters showed more overlapping than 

 the figures given in Clancey's paper, and at best were not more than a 

 slight average difference, hardly enough to warrant nomenclatorial 

 recognition. 



Using only breeding season examples, to eliminate possible migrants 

 of the other population, I found that in males the wing length varied 

 from 190 to 223 in Mediterranean birds, from 185 to 218 in southern 

 ones : The tail length in these males varied from 186 to 226 in Mediter- 

 ranean examples, from 181 to 219 mm. in southern ones. The females 

 showed similar overlapping. Finally, as a test, I found myself unable 

 to relegate the majority of specimens to subspecies without looking 

 at the localities on their labels. I therefore do not accept choragium 

 as a valid race, at least not as a race of utility in taxonomic work. 



It may be mentioned that I examined these birds with the expecta- 

 tion that choragium would be corroborated, as I was aware of interest- 

 ing differences in the host relations and host-parasite adaptations in 

 the two populations. I can only look upon the results as providing 

 unexpected support for the relative recency of this cuckoo as a breed- 

 ing bird in sub-Saharan Africa, a conclusion already suggested by a 



