176 LANIAD^. 



many birds build nests and produce young before they 

 have attained their own adult plumage. 



Baron Cuvier has stated, that when the adult female 

 bird differs from the male in the colour of her plumage, the 

 young birds of both sexes, in their first feathers resemble 

 the female ; the young males afterwards putting forth the 

 colours that indicate their sex. When the adult male and 

 female are of the same colour, the young then have for a 

 time a plumage peculiar to themselves. The Pheasant 

 may be quoted in illustration of the first law, and the 

 Partridge as an example of the second. To these two, a 

 third law may be added : whenever adult birds assume a 

 plumage during the breeding season decidedly different in 

 colour from that which they bear in the winter, the young 

 birds of the year have a plumage intermediate in the ge- 

 neral tone of its colour compared with the two periodical 

 states of the parent birds, and bearing also indications of 

 the colours to be afterwards attained at either period. 



There are various modes by which changes in the ap- 

 pearance of the plumage of birds are produced. 



By the feather itself becoming altered in colour. 



By the bird's obtaining a certain addition of new feathers 

 without shedding any of the old ones. 



By an entire or partial moulting, at which old feathers 

 are thrown off and new ones produced in their places. 

 And by the wearing off the lengthened lighter-coloured 

 tips of the barbs of the feathers on the body, by which 

 the brighter tints of the plumage underneath are exposed. 

 These changes will be noticed under the different species 

 most affected by them. 



