436 SYLVIID/K 



quills beneath greyish-brown : legs, toes and claws, pale 

 brown. 



The whole length of the bird is about five inches ; from 

 the carpal joint to the end of the longest primary, two inches 

 and a half; but, as has been mentioned (page 354) of the 

 Wheatear and as is probably the case with many other widely- 

 ranging birds, this measurement is subject to much variety : 

 the first primary comparatively long ; the second longer than 

 the sixth, but not quite so long as the fifth which is shorter 

 than the fourth. 



The females scarcely differ from the males either in size 

 or plumage ; and these birds moult as soon as the breeding 

 season is over. 



Young birds in the autumn are decidedly yellower than the 

 adults at the same season, and this tinge is retained to some 

 extent till the following spring. 



The characters which distinguish the Wood- Wren from 

 the present species have been already pointed out. Though 

 minute some of them are unfailing, and especially that 

 afforded by the size and shape of the first primary. It is 

 far harder to separate the Willow- Wren from the Chiffchaff, 

 yet the two species are perfectly distinct. The Willow- Wren 

 is usually much the larger bird, and in fresh specimens of 

 the adult of each the colour of the legs is sufficiently diag- 

 nostic ; but practised ornithologists have been known to be 

 uncertain if not to fail in discriminating the young, and even 

 preserved specimens of the adult, for though generally the 

 greener colour of the Willow- Wren above, and its whiter 

 belly serve as a guide, these cannot always be trusted, any 

 more than occasionally the form of the wing and the relative 

 proportion of its primaries. It is believed, however, that in 

 the Willow- Wren the third, fourth and fifth primaries have 

 their outer web suddenly narrowed towards the tip, while in 

 the Chiffchaff the sixth has also the same shape, but not 

 always the third*. 



* This little matter may affect some people more than might at first appear, 

 for by a recent Act of Parliament (35 and 36 Viet. chap. 78) the Chiffchaff is pro- 

 tected, while the Willow- Wren is not. To these birds the Act cannot much signify. 



