36 U.S. NATIONAL MUSEUM BULLETIN 2 65 



croA^Ti of the tree and a rather slow raising and lowering of the A\-ings, 

 often not in perfect synchronization, giving an impression of alterna- 

 tion or an attempt to balance." 



Similar communal display antics have been described for C. lucidus 

 by Edgar (1960, p. 134), by Fitzgerald (1960, pp. 9-10), and by Watson 

 and Bull (1950, p. 226), while Mathews (1918, p. 358) quoted his cor- 

 respondent Alattingley to the effect that he had noted six or seven 

 males simultaneously courting a single female, but not in a pursuit 

 flight like the cases described above. Mattingley noted that the cock 

 bird stretches its wings and then leans forward so that its metaUic- 

 green back feathers show up clearly; "should the bird be in the sun- 

 light, the colour of its green back is most Aavid, and appears like shot 

 silk. ..." A somewhat similar, but also different, courtship pose is 

 taken by the male of C. klaas, according to Winterbottom (1939, p. 

 716), who "UTote that the ordinary display is given high up in trees, and 

 therefore is seldom witnessed. He saw a male, perched about a foot 

 from a hen, go through a series of twistings of the body from side to 

 side without mo\4ng its feet, ^^-ith wings partly spread and drooped, 

 and ^^'ith the taU partly spread. Here again it woidd appear that the 

 sideways movement of the courting male is a device for catching the 

 sunlight on its glossy feathers and making them shine during the 

 performance, like the more vertical movements of C. lucidus. It is 

 nothing new, but yet serves as a cause for perennial consideration that 

 special plumage colors are related to special movements by which 

 they are utilized in the ethology of thek wearers. 



Features of brood parasitism in 

 Chrysococcyx 



Host selection and its evolution 



In our discussion of the phylogenetic relationships of Chrysococcyx 

 to Cacomaniis and Cuculus it was pointed out that the glossy cuckoos 

 probably developed out of the stock of which these groups are the 

 present representatives and that these genera are very similar in 

 many ways. It is not svirprising, therefore, to find that their host 

 preferences are fairly similar also. This is particularly true for Chryso- 

 coccyx and Cacomaniis. The hosts chosen by both are smaU, insectiv- 

 orous, passerine birds, and not a few of the species used are parasitized 

 by cuckoos of both genera. It is true that there have been reported 

 a very few instances of glossy cuckoos depositing their eggs in nests 

 of mousebirds, kingfishers, barbets, and woodpeckers, but some of 

 these may be erroneous, or, at best, may be looked upon as unusual, 

 if not accidental, host choices. 



In areas where there are a number of kinds of parasitic cuckoos vdth 



