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U. S. NATIONAL MUSEUM BULLETIN 217 



of recent instability among the animals of the Alaskan tundra. There 

 are no records to show how the other animal populations have been 

 changed, but the lack of evidence of depletion suggests that the arctic 

 interior of Alaska is exceptional for the retention of conditions as 

 they were established by the natural progress of erosion and climate. 



These considerations, together with the results of my own travels 

 and observations, and the reports of the few naturalists who carried 

 their observations through the seasons until they obtained compre- 

 hensive views of the avif amia, allow me to believe that I can present 

 a comparative view of the natural distribution of birds in arctic Alaska 

 and Yukon. 



In the description of each species at Anaktuvuk, Kobuk, and Old 

 Crow (chapters 2-4), I have discussed the season when the birds 

 are present, their migration, and their nesting. In table 4 I have 

 summarized the information about their seasonal stay at these locali- 

 ties in terms descriptive of the seasonal extent and main biological 

 function served by their presence. I have used the characterization 

 "visitor," which for us would imply a purpose, to designate only the 

 appearance of certain birds without evidence that they carry out 

 activities related to breeding. At Anaktuvuk, for example, all the 

 species called visitors are known to nest within a few hours flight, 

 and most have been seen frequently and in good condition, so their 

 appearance there gives no evidence of abnormality. Inasmuch as the 

 designation of birds as "visitors" defines an activity which appears 

 normal, however, it does include the implication of biological purpose 

 often suggested by a regular form of animal behavior. 



Table 4, — Status of hirds at Anaktuvuk, Kobuk, and Old Crow 



[Explanation— (R) resident, (RM) resident and migrating, (M) migrating but not remaining to nest, 

 (MN) migrating to nest and also migrating, (N) migrating to nest there and not migrating farther, (V) vis- 

 itor, (W V) winter visitor. (O) not present.] 



Species 



A- 

 nak- 



tu- 

 vuk 



Ko- 

 buk 



Old 



Crow 



Species 



A- 

 nak- 



tu- 

 vuk 



Ko- 

 buk 



Old 

 Crow 



Gavia immer 



MN 



MN 



MN 



Anas platyrhynchos platy- 









Gavia adamsii 



MN 



M 







rhynchos 



M 



N 



MN 



Gavla arctica pacifica 



MN 



MN 



MN 



Anas acuta 



MN 



MN 



MN 



Gavia stellata 



MN 



MN 



MN 



Anas carolmensis 



MN 



MN 



MN 



Total Gavhdae (4) 



(4) 



(4) 



(3) 



Mareca amerlcana 



MN 



MN 



MN 



Podlceps grisegena holbollii 







N 



N 



Spatula clypeata 



M 



MN 



MN 



Podlceps auritus comutus 



V 



N 



N 



Aythya marila nearctica 



MN 



MN 



MN 



Total Podicipedidae (2) 



(1) 



(2) 



(2) 



Aythya affinis 



MN 







MN 



Olor columbianus 



M 



MN 



MN 



Bucephala clangula amerlcana 











M 



Branta canadensis tavemeri 



M 



MN 



MN 



Bucephala Islandica 



o 







M 



Branta nigricans 



M 



M 



M 



Bucephala albeola 







N 







Anser albifrons frontalis 



M 



MN 



MN 



Clangula hyemalls 



MN 



MN 



MN 



Chen hyperborea hyperborea 



M 



M 



M 



Hlstrlonicus hlstrlonlcus 



MN 



MN 



MN 



