BIKDS OF ETHIOPIA AND KENYA COLONY 265 



form, and the distribution of forest is exceedingly patchy and broken 

 in northeastern and eastern tropical Africa. This cuckoo has been 

 found in southern Ethiopia (in the four localities mentioned above), 

 in the Bahr-el-Ghazal region of the Sudan, in Uganda, and in two 

 localities in Kenya Colony, the slopes of Mount Kenia, and the 

 Kakamega-Kaimosi forest between Mount Elgon and Kavirondo 

 Gulf. 



The Juvenal and immature plumages of this bird and the closely 

 related dmnosits are not yet thoroughly understood, and undoubtedly 

 much that is puzzling in the distribution of clcbmosus in its winter 

 range will depend for its solution upon a careful study of the molts 

 of these forms. The work, however, must be done in the field, not 

 in the museum. In his valuable notes on these birds Bannerman *^ 

 writes that the problem of identifying subadult birds is rendered 

 almost hopeless, since " * * * unfortunately both forms occur 

 side by side in many districts — even in the same forests." While 

 in general this is true (one of the birds collected by Mearns was shot 

 together with a migrant cIa7nostcs), it seems that more frequently 

 it would be found that the two did not occur, " * * * gyen in the 

 same forests." In my own field experience with these cuckoos I 

 always found damosus in thornbush country, in Acacia-Mimosa 

 thickets and savannas, while chalyheus was met with only in forests. 

 I think that in the absence of field studies, if museum workers hav- 

 ing ample material would put all forest specimens on one side and 

 birds from savannas and bushveldt on the other, they might be able 

 to work out the plumage changes of each. The migrant dannos'm 

 could be distinguished in many cases by dates and by the degree of 

 abrasion of the feathers. Of course, it is not to be expected that 

 cJialybeus never gets out of the forest or that dmnosus never pene- 

 trates wooded areas, but all such doubtful specimens could be ignored 

 in such a study. The present form is obviously a northern race of 

 damosus^ being the forest-inhabiting aggregate of the species. 



I have not the material on which to base a survey of the plumages 

 and molts of the races of tlfts cuckoo, but for the benefit of anyone 

 who has and cares to make the study I append the following facts : 



An immature female chalyheus from the eastern Belgian Congo, 

 now in the Museum of Comparative Zoolog}^, is entirely dark fuscous 

 brown, but is molting into immature plumage on the undei-parts. 

 The new feathers on the breast and abdomen are dark fuscous nar- 

 rowly barred transversely with rufous and dull buffy. This speci- 

 man agrees with another recorded by Bannerman," and indicates 

 that the juvenal plumage is probably wholly dark fuscous brown; 

 the immature plumage more like that of the adult, but with both 



" Ibis, 1921, pp. 92-95. 



