191 7-1 Breeding-habits of the Cuckoo. IS* 



Theories, indeed, have multiplied exceedingly, as is in- 

 evitable when facts are few. Many of these theories verge 

 on the fantastic, while others have been evolved by an 

 apparent confusion of cause and effect, and facts have been 

 twisted to fit them. 



As a result, it is not difficult to understand that tlie 

 Cuckoo is regarded, by many people as being absolutely 

 distinct from all other species in its habits, and as possessing 

 many extraordinary endowments to assist it in its parasitical 

 methods of reproduction. 



The difficulties in obtaining any conclusive information 

 on many doubtful points are, indeed, so great that it is not 

 easy to see how they can be overcome. In addition to the 

 initial impossibility of identifying one female from another, 

 the male in this species unfortunately resembles his mate so 

 closely that it can only be distinguished at a distance by the 

 note, while its polygamous habits, and the fact that, unlike 

 other birds, it is not more or less tied down to the vicinity 

 of its nest, makes observation of any specific female, and a 

 computation of the numbers resident in any district, an 

 almost hopeless task. 



Cousequently, it seems that if we are ever to solve the 

 problem it must be by a combination of lucky chances, and 

 by carefully piecing together, as in a detective mystery, the 

 various clues which come into our possession ; and it is 

 thus of great importance that no available information shall 

 be overlooked or remain uunkown. Hence, in this paper, 

 I propose to review the facts we possess, and to examine 

 some of the more important theories, in the hope of inter- 

 es.ting others in this subject, and indicating the points on 

 which further information is required. 



The authentic facts knoivn. 



The actual facts we possess, as distinct from conclusions 

 and theories, may be summed up as follows : — 



(a) Our Cuckoo (C. canorus), in common with most of 

 its family, places its eggs in the nests of other birds, leaving 

 to them the duties of incubation and rearing the young. 



