102 Loomis on Birds of Chester County, South Carolina. \ April 



Leconte's Sparrow from the interior to the South Atlantic 

 States, or of the Bobolink in middle latitudes across the 

 equator, or of the American Golden Plover from Arctic far 

 toward Antarctic regions, the result is, that the life of the 

 north is so adjusted that the dearth of winter is avoided. 



The following description of the northward movement is based 

 chiefly upon my 'Observations on Migrations' (Auk, IX, pp. 

 30-33) and upon the 'Study of the Bird Waves which passed 

 up the Mississippi Valley during the Spring of 1884' (R e P- Bird 

 Migr., pp. 25-37). While the southward movement, save in 

 its latter stages in the case of prolonged warmth, is an uninter- 

 rupted evacuation of the region that cannot be held in winter, 

 the northward movement is a reoccupation that is successively 

 obstructed, interruption finally ceasing only when the bands of 

 winter are broken in Arctic regions. Mallards, Canada Geese, 

 etc., among water birds, Robins, Red-winged Blackbirds, etc., 

 among land birds persistently press against the barrier of snow 

 and ice, following in its wake as it recedes northward and 

 retreating for the time being as it temporarily advances south- 

 ward. Behind these come other birds of the same species in 

 greater abundance, and White-throated, Song, and Field Spar- 

 rows, Killdeers, Wilson's Snipe, Meadowlarks, etc. Crowding 

 upon these in turn come the hosts of highly insectivorous species, 

 the last representatives of the earlier species, and those that 

 habitually fetch up the rear of the migration. Migration may 

 be arrested at the north and at the same time be under full 

 headway at the south, movements taking place and territory 

 occupied north or south as soon as it becomes tenantable, even 

 though it be but temporarily so. So eager is the spirit to return 

 that even the Swallows venture north before winter is hardly 

 gone. At Saint Michaels, Alaska, according to Mr. Nelson 

 (Rep. Nat. Hist. Coll., pp. 197, 19S) the first Barn Swallows 

 arrived during the latter half of May when the sea was covered 

 with an unbroken surface of ice as far as the eye could reach. 

 Frosty nights and snow-squalls were endured apparently without 

 harm, shelter being found in old nests and other snug places 

 until the sun shone once more. 



Mr. Murdoch states (1. c, p. 116) that the spring migration 

 at Point Barrow takes place from the middle of May to the end 



