4 BIKDS AND MAMMALS OF EAST SIBERIA [^' Vof. V ' 



winter climate, where 85 degrees below zero Fahr. is not unusual ! 

 And yet there is at the Kolj^ma a quite varied winter bird fauna. 



Following is a list of the species seen and taken by Mr. Koren 

 from the time he rounded East Cape in the summer of 1911, until 

 he was shipwrecked at Cape Unikin in the autumn of 1912. 



Among them will be found three American species — the pectoral 

 sandpiper, the northern bald eagle and the gray-cheeked thrush. 

 These birds have become established in arctic East Siberia as breed- 

 ing species, probably in recent years, just as several Siberian forms 

 have worked their way eastward and have established themselves 

 in Alaska. 



Tetraonidae. 



Lagopus lagopus koreni subsp. nov. 



Seventeen specimens, both sexes, representing both summer and 

 winter dress, were taken at Nijni Kolymsk in October and Decem- 

 ber, 1911, and in May and June, 1912. Full winter plumage was 

 acquired by October 7, on which date birds were shot with no trace 

 remaining of the summer dress. In spring a bird taken May 8, 

 has the whole neck brown, the head still white. In birds killed 

 a month later the whole head, neck and interscapulars are brown, 

 and there are some brown feathers in the longer wing-coverts, 

 the rest of the plumage being white. On June 5 an uncolored egg 

 was taken from the oviduct of a bird killed that day, and on June 

 22 a clutch of fresh eggs was secured. The nest was in a patch 

 of creeping willow in dry larch forest. 



Upon comparing this series with extensive material from various 

 other regions, we have come to the conclusion that the ptarmigan 

 of arctic Eastern Siberia must receive a name. Compared with 

 the West European Lagopus lagopus lagopus (Linn.), the East 

 Siberian bird is at once distinguished by its very large bill. It 

 therefore needs no comparison with the small-billed form, L. lago- 

 pus bredrostris Hesse, of the Altai Mountains. Lagopus lagopus 

 major Lorenz, from the steppes of Akmolinsk, Orenburg and Turgai, 

 we have not seen, but the description indicates a different bird from 



