1 66 Wild Life in Wales 



I examined a bird, in precisely similar condition, in June 

 some years ago. 



This opens up an interesting question regarding the 

 change of plumage in the Cuckoo, which is not very 

 generally understood, and is mostly passed lightly over in 

 text-books. It is now pretty well recognised that many of 

 our birds moult only once a year, and that during summer ; 

 but it is not so generally known that a considerable differ- 

 ence in regard to time of moult frequently exists between 

 the sexes. The possible reasons for this discrepancy I may 

 have an opportunity for touching upon later, at present it 

 is enough to accept the fact, and to admit that the habit is 

 not confined to any one particular family. The moult of 

 our common Cuckoo may serve as an illustration in point. 

 To a considerable extent its change of plumage is effected 

 during our winter, when the bird is in warmer climates, but 

 this is certainly not an unvarying rule. A large majority 

 of the Cuckoos, 1 when they arrive in this country, in May, 

 appear to have already completed the growth of their new 

 feathers ; some of them, on the other hand, have un- 

 doubtedly not done so ; while in a few cases at all events, 

 the young of the previous year appear to return in the same 

 dress in which they left us in autumn, and to breed in that 

 state. The feathers are somewhat faded and worn ; but in 

 many cases, if not always, they seem to be retained at least 

 until the approach of mid-summer, and frequently till an 

 even later period. I have several times met with Cuckoos 

 up till as late as the last week in June, which appeared to 

 be in nearly perfect red plumage (i.e. in a dress similar to, 

 if not identical with, their first feathers). I have actually 

 heard such birds calling " cuckoo," and have proved by 

 dissection that they were breeding ; but the few whose 

 remains I have handled have always been more or less in a 

 state of moult as regards their body feathers. As all old 

 Cuckoos leave this country early in July, some of these red 

 birds could scarcely have time to complete their moult 



1 It may be worth while noting, in this connection, that male cuckoos 

 seem generally to largely outnumber the opposite sex ; a fact not easily 

 explained, but one which is not confined to this bird only. 



