ANAKTUVUK PASS 57 



thought that geographical races of Tetrao urog alius living in lands 

 about the Baltic Sea were distinguishable, although not recognizable 

 by superficial taxonomic distinctions. Near the northern limits of 

 spruce in the interior of Keewatin 6 adult males of Lagopus lagopus 

 albus taken between May 31 and November 7 averaged 631 grams in 

 weight ( Harper, 1953 ) . 



Considering the variations in weight of domesticated animals which 

 can be produced by feeding one would conclude that differences in the 

 natural nourishment provided in parts of the range of a species could 

 easily account for the differences in weight of grouse found in several 

 distinct localities. Among the wild birds of Anaktuvuk, however, I 

 find that the differences in weight among individuals of specific popu- 

 lations are small and they are evidently homogeneous in respect to 

 weight. I am inclined to favor von Zedlitz's suggestion that genetic 

 differences are likely to be at the basis of the distinction of weight 

 in certain parts of the range of grouse. Nasimovitch (1936) reported 

 an increase in the weight of Lagopus lagopus progressing eastward 

 into that part of their range lying in the central regions of western 

 Siberia. 



In the years under observation (1947-1957) the abundance of willow 

 ptarmigan in winter at Anaktuvuk has varied from their being com- 

 mon to very common. I have not found evidence for regular cycles of 

 abundance. The difference in actual numbers seemed to be as much as 

 ten fold, and I suspect that some orderly conjunction of events under- 

 lies the phenomenon. As no annual differences have been observed in 

 their weight and condition of flesh the good nutritional condition of 

 willow ptarmigan in winter is a characteristic of the season and locality 

 in spite of the fluctuations in numbers which at times appeared to 

 crowd the country with ptarmigan. It also seems that in the sub- 

 arctic locality a distinction in weight occurs, although we have seen 

 no superficial character to distinguish them from birds of other 

 localities. 



Lagopus rnutus nelsoni Stejneger 



9 males 



May 8-July 14 



weight (20), 411-559, 

 average 466 g. 



8 females 



May 8-June 5 



weight (7), 416-480, 

 average 427 g. 



1 marked female, 



July 31 



weight 412 g. 



but in male 







plumage 







2 downy males 



Julys 



weight 15.2, 16.3 g. 



These Nelson's rock ptarmigan correspond in beak size and in the 

 distinctive summer pattern of males to those marked nelsoni in the 

 U. S. National Museum. 



As Niksaktongik, rock ptarmigan are nearly as well knoAvn, and 

 form a more interesting part of Nunamiut life than are the larger wil- 



