AVIAN GENUS CHRYSOCOCCYX 3 



the evolutionary history of the glossy cuckoos. The morphological 

 differentiation of the group as evidenced by the apparent phylogenetic 

 relationships of the existing forms is presented in detail. Follomng 

 this, the comparative data on migratory behavior are described to 

 help explain the present geographic distribution of some of the various 

 species of the group. The similarities and the differences in the court- 

 ship habits of the species are then considered for the glimpses of past 

 history they reveal. With this background as a basis we then discuss 

 each important behavioral segment of the parasitic habit in the 

 glossy cuckoos, with all the data pertinent to the problem of host 

 selection and its evolution; of host specificity; of egg morphism and 

 its importance as evolutionary material; of the mode of egg-laying by 

 the parasites; of removal of host eggs by the cuckoos; and of the highly 

 specialized relations between the nestlings of the hosts and of the 

 parasites. This is followed by a discussion of all that is known of the 

 eviction of nestmates by the nestling cuckoos and of fledgling feeding 

 by the adults. Both of these behavior patterns are highly significant 

 in the biological history of the glossy cuckoos. 



All these data and all the ideas pertinent to them are then brought 

 together and summarized. An appendix provides in its first part a 

 distributional check list of all the members of the genus Chrysococcyx 

 and in its second shorter part, brings together the earlier and the 

 more recent knowledge of the plumages of one species, hitherto very 

 inadequately described. 



Phylogenetic relationships 



Figure 1. Geographic range of the genus Chrysococcyx. [Shaded area in the Austro- 

 Malaysian region should be taken to refer to land areas only.] 



