286 BRITISH HIKDS. [vol. x. 



throat and breast smoky instead of huffish. As compared 

 to the juvenile Willow- Wren the upper-parts are darker, 

 the throat and breast more smoky and the belly whiter and 

 not so yellow. 



First Winter. — The juvenile body-feathers and wing- 

 coverts are moulted in August and September, but not the 

 primary-coverts nor the wing- and tail-feathers First 

 winter birds cannot be distinguished from adults. 



Scandinavian C'hifpxhaff {Ph. c. abietinus). 



Moults as in Ph. c. collybita, but the autumn moult is 

 often not complete before October. In winter the bird is 

 like Ph. c. collybita in coloration, but in sjoring and summer 

 the upper-parts are paler and more greyish with very little 

 green and the under-parts are whiter and less buff anrl 

 yellow. 



Siberian Chiffchaff (Ph. c. tristis). 



Moults as in Ph. c. abietinus. In winter the upper-parts 

 usually have a tinge of green, but in smniuer thej' are still 

 browner with usually no trace of green. 



Willow-Warbler {Ph. t. trochilus). 



Adults.— Complete moult in July and August, sometimes 

 beginning in June. From December to March another 

 complete moult takes place. There is no sexual difPerence in 

 the plumage. The new spring plumage is like the winter, but 

 perhaps slightly less green and more brown on the upper- 

 parts, and as summer advances abrasion makes the upper- 

 parts still browner and the under-parts whiter. 



Juvenile. — Much as the adult, but the upper-parts brown 

 with only a tinge of olive, belly very pale lemon-yellow and 

 not white as in the adult, u]5per-breast dusky-buff. 



P'iRST W^inter.— The juvenile body-feathers are moulted 

 in July and August, but not the wing-coverts, wing- or tail- 

 feathers. First winter birds are more yellowish-brown on 

 the iipper-parts and much yellower on the under-parts than 

 adults, the throat and breast being a much deeper yellow 

 and the belly only a shade paler instead of white as in the 

 adult. 



First Summer.— Moult as in the adult after which they 

 become like the adults. 



Northern Willow-W^arbler {Ph. t. eversmanni). 

 Adults. — Moults as in Ph. t. trochilus. In the winter it is 

 impossible to distinguish satisfactorily from Ph. t. trochilus. 



