( '29 ) 



ON THE MOULT AND COLOUR CHANGES OF 

 THE CORNCRAKE (CREX PRATENSIS). 



By J. L. Bonhote. 



Having for several years successfully kept, and on one 

 occasion* bred, the Corncrake {Crex pratensis) in confinement, 

 and having also had several wild caught specimens through my 

 hands during the same period, the following results of my 

 observations on the moult and colour change of this species 

 may prove of some interest. In common with many other birds, 

 the Corncrake has two moults in the year, the chief one taking 

 place in July and August, as soon as the breeding season is over, 

 and involving a change of every feather ; the other taking place in 

 February, while they are still in their winter quarters, and 

 involving a change of all the feathers except the tail and wing 

 quills. In the autumn moult the primaries and secondaries in 

 both sexes are thrown off simultaneously, and for about ten days 

 the birds are totally incapable of flight. On two occasions I 

 have had wild birds brought in which had been captured when in 

 this condition. 



The males can be easily distinguished from the females 

 during the summer months, as the breast, neck, and sides of the 

 head are during that time of a delicate slaty grey colour. The 

 plumage of the female hardly differs throughout the year. 



At the autumn moult, however, the males lose the slate- 

 colour on the breast and neck, and assume a plumage similar to 

 that of the females. 



The plumage assumed after the spring moult is precisely 

 similar in both sexes to that which has just been discarded ; in 

 the male, however, the feathers on the breast and head, as soon 

 as they are fully grown, begin to assume, by a change of colour, 

 the bluish tinge of the breeding-season dress, and, as summer 



* See Zool., 5th ser., vol. i., p. 35. 



