290 U. S. NATIONAL MUSEUM BULLETIN 217 



in conversation and discussion upon the events of natural history. 

 In this way all observations made in the village were brought into 

 a pool from which Simon Paneak and I could study in careful, critical 

 discussion the details and circumstances by which the migration was 

 marked. 



Often numerous individuals of the commoner species are seen on 

 the same day in spring when they are first reported. Within a few 

 days the presence of the common species is familiar to all the 

 people. Thereafter new arrivals of the species may be distinguishable. 

 The early arriving snow buntings are followed by successive flocks 

 which continue to move northward for as long as 6 or 7 weeks. The 

 early eagles all arrive within a period of 2 weeks. Golden plover 

 continue to gain new migrant arrivals for about 2 weeks, but Baird's 

 sandpipers seem to arrive during a shorter time, as do robins, 

 Gambel's sparrows, and Smith's longspurs. The arrival of migrants 

 appeared to be concentrated in the latter part of the season. 



If the appearance of migration is compared with a moving wave, 

 its crest occurs several days after its initial appearance. The length 

 of the waves certainly differs among the species by as much as from 

 1 to 6 weeks. But if the analogy of migration to a wave is pursued, 

 the initial appearance is a characteristic presaging the birds which 

 follow. The first birds which arrive are seen as individuals or as 

 flocks which are fewer than the entire migration. Since the birds of 

 a population are coherently related, their average behavior and con- 

 dition indicate the normal characteristics of their coherent action. 

 On the other hand certain occasional behavior is seen which is incon- 

 sistently related to migration. These observations of aberrant be- 

 havior cannot be used in describing the progress of migration. 



Migratory birds arriving at Anaktuvuk either settle there to nest 

 or they proceed northward as far as the arctic coast. There is no 

 likelihood that significant numbers pass eastward or westward beyond 

 arctic Alaska. No Alaskan land lies more than 200 miles north of 

 Anaktuvuk, and the geographical center of the arctic slope north 

 of the Brooks Eange is less than 100 miles distant. The location of 

 Anaktuvuk is accordingly within a few hours of the limit of north- 

 ward flight overland in this sector and thus is near or at the terminus 

 of migration. We may say that, practically, the locality is the northern 

 terminus and that the condition of the migrant birds represents their 

 state upon arrival from a long migration to an arctic region. Con- 

 sidering the rapidity of change in behavioral and physiological proc- 

 esses in birds about to nest, there will be some loss of physiological 

 detail in considering all these migrants through Anaktuvuk alike as 

 birds that have reached their breeding grounds, yet they indicate 

 better than do those at lower latitudes the general condition at the 

 terminus of migration. 



