Birds observed in Kamchatka. 273 



Island form, includes Southern Kamchatka in the area of its 

 breedings-grounds. The sixth, Nucifraga kamchatkensis, is 

 merely the differentiation locally of a bird already well known 

 to be (in one form or another) Kamehatkan ; while as to a 

 possible seventh, viz. Larus canus, I am uncertain whether 

 this species be really an addition to the Kamehatkan list. 

 Kamehatkan specimens have been usually referred to the 

 seemingly almost identical L. kamchatkensis. 



The composition of the Kamehatkan avifauna is well 

 shown by the following table, which I take from Dr. Stejneger. 

 A peculiar feature is the large proportion (over 56 per cent.) 

 of swimming and wading birds. Of his 175 species 



39 are Circumpolar, or about 22'3 per cent. 



37 „ Palcearctic, ,, 21 '1 „ 



28 „ Pacific „ 16 



8 ,, American, ,, 4"6 „ 



9 „ Siberian, ,, 5*1 „ 

 54 „ East Asiatic ov \iccw\\2LV*, „ 30*9 „ 



Including the Nutcracker, only 11 species or subspecies 

 are peculiar to Kamchatka. All these (except Halia'etus 

 hypoleucus Ridgway, the status of which is doubtful) are 

 "representative" forms of species which are of considerable 

 variability, and possess corresponding '' representative con- 

 species or subspecies in the different provinces of the 

 Palsearctic region. '^ The nature of the modification under- 

 gone by these peculiar forms is of great interest. To quote 

 Dr. Stejneger — ''In every instance it consists in an increase 

 of the white colour as compared with the nearest allied forms. 

 In fact, all the peculiarly Kamtschatkan birds possess a 

 greater amount of white than any of their allies, wherever 

 these may reside. So extreme is this tendency towards 

 whiteness that one species, Astur candidissimus, has become 

 entirely white, while another, Parus kamtschatkensis, is nearly 

 so.'^ The increase of the white colour is not in the nature 

 of a bleaching or fading of the darker colours, but a simple 

 replacement of them by pure white. Parts of the body 



* In this category are included forms which do not ordinarily occur 

 west of the river Yenisei. 



