ADDITIONAL CUCKOO NOTES. 891 



eggs would certainly seem to have adapted itself to that of the type of 

 fosterer's egg with which it is generally found. 



Of the genus, Hierococcyx, the Large Hawk Cuckoo, which in the 

 Eastern Hills places its eggs in the nest of the Large Spider Hunter 

 (Arachnothera magna), in perhaps four cases out of five has an egg 

 which very closely resembles that of its foster-parent and is rough- 

 ly speaking an olive brown. But this bird in the Khasia Hills and 

 also in the Himalayas would seem to place its eggs in the nests of birds 

 of the Garrulax group, Myiophoneus or others which lay blue or blue 

 spotted eggs, and accordingly we also find that it has developed a blue 

 egg which resembles the olive type in nothing but shape and texture. 



The Common Hawk Cuckoo (Hierococcyx varius), as already said, has 

 arrived at complete adaptation and invariably places its deep blue eggs 

 in nests of fosterers which lay the eggs of a similar colour. 



As regards the Small Hawk Cuckoo (Hierococcyx nisicolor) it appears 

 to deposit its eggs, as a rule, in the nest of birds which lay eggs by no 

 means conspicuous and which do not differ greatly in colouration from 

 its own egg, but our knowledge at present does not enable us to say 

 that it has any predilection for any particular foster-parent for its 

 young. 



We then come to the genus Caccomantis, Professor Burnett's friend, 

 and here are confronted by one of the most remarkable instances of 

 what appears to be adaptation. Normally the bird in the South of 

 India, Belgaum and Kanara, where it is most common, and also in the 

 Nilgiris, lays its eggs in the nests of the Fantail Warbler ( Cuticola 

 cursitans), the common Tailor-bird ( Orthotomus sutorius) and the Indian 

 Wren Warbler (Prinia inornata). Now all three of these species lav 

 eggs which are white or blue in ground colour and are more or less 

 spotted ; accordingly the Cuckoo has developed an egg of the same 

 description which is an enlarged facsimile of the Tailor Bird's eggs and 

 not very strikingly different from those of other birds. In the Deccan, 

 however, the Plaintive Cuckoo has deserted these fosterers and relies 

 on the Ashy Wren Warbler (Prinia socialis) to bring up its young ; 

 accordingly the eggs seem to be in the course of adaptation to its 

 requirements, and whilst some are intermediate in colouration between 

 the normal Southern Indian egg and the terra-ootta type, and appear 

 to show incomplete adaptation, the majority are of a terra-cotta colour 

 which is inconspicuously different from that of the eggs of the Prinia. 



