AVIAN GENUS CHRYSOCOCCYX H 



in the mountain forests at altitudes of from 2000 to 3300 meters, and 

 occasionally down to 1300 meters according to Mayr (1941, p. 73). 

 Fuller knowledge may reduce ruficollis to the status of a race of 

 malayanus, as was suggested by Rensch (1931, p. 544) who pointed 

 out that the two species do not overlap in their breeding ranges. Mayr 

 (1932) suggested that the tail pattern of ruficollis raised the possibility 

 of its close relationship to lucidus, and noted that the solution of this 

 problem must await fuller knowledge of the vocalisms, habits, and 

 eggs of these cuckoos. 



The other species, C. meyerii, however, is, very distinct. Between 

 it and the stock of which malayanus seems to be the least changed 

 representative, there is a gap in the existing evidence. Not only is it 

 more brightly metallic on the upperparts, but the female has a wholly 

 new plumage character, with a bright-chestnut forehead and anterior 

 portion of the crown. This is the only species of the entire genus in 

 which this marked, brightly colored character has developed in the 

 female. The fact that the young of this species is unhanded below is 

 evidence that C. meyerii is related to the other Indo-Australian species. 

 It may be noted, at this point, that Iredale (1956, p. 185) has made 

 some comments about this species, which do not tally with the infor- 

 mation in his own book. He writes that the immature "is so unlike the 

 adult as to raise suspicion about all the distinctions cited in favour 

 of the separation of these Cuckoos by means of tail coloration. The 

 young bird, figured on Plate XII, Figure 9, shows no bronze above, 

 only a dullish green, while it is whitish below , . .," but the colored 

 figure he gives shows the entire upperparts of the bird from forehead 

 to tail pale chestnut-brown! C. meyerii is distinguished in both sexes 

 by a broad chestnut area in the remiges, by its brightly glossy-green 

 upperparts, and by its small size. 



C. meyerii is a critical species in the evolutionary vicissitudes of 

 the genus. Not only is it the first expression of a trend toward bril- 

 liantly colored forms — a trend that again reveals itself in two species 

 of the Asiatic mainland, C. maculatus and C. xanthorhynchus — but it 

 is the first species (in this reconstructed phylogeny) that possesses 

 very distinct sexual plumage dimorphism. It is also the last species in 

 our present arrangement to possess the character of largely unmarked, 

 uniformly grayish or brownish ventral plumage in the young, agreeing 

 in this important respect with all the Australasian species and differing 

 from the two Asian and all the African ones, the young of w^hich are 

 very strongly banded over the entire underparts. In some of the 

 Australian and Malaysian species the sides and flanks of the young 

 are banded, but these cross marks do not extend across the breast or 

 abdomen, and even in these species occasional completely unhanded 

 individuals occur {C. I. plagosus, Mayr, 1932). 



