RESIDENCE IN THE ARCTIC 313 



Flockt compact Flocka coherent but not compact Southward movements loosely 



associated but apparently coherent 



Anas acuta (cT) Clangula hyemalis Eremophila alpestris 



Aythya marila ( c?) Ereunetes pusillus Motacilla flava 



Melanitta deglandi (c?) Sterna paradisaea Anthus spinoletta 



Turdus migratorius Acanthis hornemanni Calcarius lapponicus 



Calcarius pictus 



While they are molting the birds of several species become very 

 retiring and they are not seen again in their earlier numbers. Some 

 common species simply disappear without any visible preparatory as- 

 sociation. I know of no behavior by golden plover which signals 

 their departure, but the birds of most species give indications which 

 suggest that they are about to depart. By various signs as well as 

 from the last sight records fair estimates can be formed as to the end 

 of their migratory departure, as given in table 27. The duration of 

 the departure on migration can be estimated, but this is the most un- 

 certain observation in the birds' program at Anaktuvuk. 



The last sight records differ so much among the species that the 

 duration of summer occupation of the arctic tundra is clearly seen to 

 vary considerably. Plovers and sandpipers leave early. From my 

 recollection of migration near Barrow some of the sandpipers and 

 phalaropes appeared there as migrating flocks later than the last rec- 

 ords for those species at Anaktuvuk. The plover and sandpipers are 

 so inconspicuous in August at Anaktuvuk that near the ground level, 

 at least, no extensive southbound flights were seen to assemble there 

 or to pass through from northern arctic Alaska. 



Numerous flocks of ducks, geese and a few flights of swans and 

 cranes are seen on their southbound course, but brant have not been 

 reported in the southbound flights. With that exception the south- 

 bound geese and ducks seem to be about as numerous as they are in 

 northbound flights. The flights seen moving southward do not alight 

 as often as they do in spring. 



I have only one record of southward movement for the snow bunt- 

 ings. A flock was seen in the high mountains at the end of August. 

 A few others have been seen in the Valley in fall, but I do not know 

 the southbound route of the large numbers which fly northward in 

 spring. Our failure to record a date for the southbound eagles and 

 shrikes is not significant because there are not many of these birds. 

 A few rough-legged hawks are seen in late summer, which suggests 

 that their return occurs for the most part unnoticed along the spring 

 route. 



