Cuckoo calls on wing when mating. 271 



There has been a good deal of debate about whether 

 the cuckoo ever calls when on the wing. I am con- 

 fident that it does so when mating, and in pursuit of 

 the hen, as many other birds do that sing not on the 

 wing at any other time ; canaries being among them. 

 I have seen and heard it thus many times : and then, 

 I can assure the reader, there is no mistake about its 

 note. And since writing the above I am glad to have 

 this confirmed by the observation of a good authority, 

 who, in the Zoologist for 1894, pp. 306-8, says : 



" When mating the cuckoo most decidedly calls 

 when flying after the hen." 



Mr. A. Holte Macpherson, in writing of the note 

 of the cuckoo, however, tells, that while other birds 

 in their courtship actually lose their senses, and their 

 heads, the cuckoo always seems intelligent, and to 

 hear all neighbouring sounds." * 



Yarrell thinks that the notion of cuckoos sucking 

 eggs, — their own, or those of other birds, — arises 

 from their undoubtedly carrying their eggs in their 

 mouth ; a fact which has been so fully observed and 

 verified that there can be no doubt whatever about it. 

 But from various facts and suggestions we have given 

 — it is clear that the piercing and sucking of eggs is 

 now common to certain species of cuckoos, and phe- 

 nomena observed in the case of others would almost 

 justify one in saying that it is in no way so absolutely 

 proved that even Cuculns canorus never condescends 

 to prick and to suck eggs ; though, in our idea, it is 

 more than possible that modification of food in his 

 case, owing to changes in land culture, etc., etc., and 

 his reliance more and more on a sort of food, which, 



* Zoologist, 1895, p. 337. 



