"'^'^'^I^^] THAYER AND BANGS — BIRDS 17 



whatever, in size, color, or proportions, that could separate West- 

 ern from Eastern individuals. 



Pelidna alpina sakhalina (Vieill.). 



Three specimens, a male in full breeding plumage from Nijni 

 Kolymsk, June 8, 1912, and two young in autumn plumage (un- 

 sexed) from Cape Serdze, Aug. 23, 1911. 



The Siberian dunlin was decidedly an uncommon bird, only 

 seen here and there along the Arctic coast of Siberia. 



Careful study of a long series of the dunlin from all over its 

 range, proves that it, like the knot, sanderling, turnstone and some 

 other waders, divides into three recognizable races. 



As Mathews keeps insisting in the cases of most shore birds, only 

 birds of the same sex should be compared; female dunlins are 

 larger than males and have longer bills. 



The three races of the dunlin, which our material reveals, are 

 briefly as follows. 



Pelidria alpina alpina (Linn.). Western Europe. Small, with 

 shortest, straightest bill; upper parts darker with less reddish; 

 heavily spotted (sometimes almost streaked) with dusky below, 

 between throat and black breast patch. 



Pelidna alpina pacifica Coues. North America. Much larger, 

 with much longer, more curved bill; upper parts paler with much 

 more reddish; much less heavily spotted with dusky below, be- 

 tween throat and black breast patch. 



Pelidna alpina sakhalina (Vieill.) East Siberia. Size and length 

 and shape of bill intermediate between that of the other two forms; 

 colors much paler than in either; upper parts very pale reddish, 

 much mixed with gray; back of neck and top of head nearly wholly 

 pale gray ; below very slightly spotted with dusky, between throat 

 and black breast patch (much less so, even, than in pacifica). 



The colors as here given are taken only from birds in breeding 

 plumage. Winter birds and young in first autumn plumage show 

 differences also, and, we think, can always be allotted to their 

 proper subspecies. 



