IOO Loomis on Birds of Chester County, South Carolina. ["ajtU 



ward movement gaining the ascendency. These local occur- 

 rences appear to be a fair illustration of what takes place 

 throughout the temperate portions of the continent under like 

 meteorological conditions. The retarding of southward migra- 

 tion through warmth has been alluded to. In the 'Report on 

 Bird Migration in the Mississippi Valley' (pp. 26, 27) an 

 instance is cited as occurring during November and December, 

 1SS3, the effect of the mild season being reported in Dakota 

 and in localities southward. 



As has been seen southward migration is a gradual depopula- 

 tion, beginning north and south before August and extending 

 over nearly half the year. A survey of the bird fauna of the 

 continent during the dead of winter shows that the great mass 

 of bird life of the breeding season has been shifted southward, 

 equalizing distribution so as to meet the conditions of winter. 

 The hyperborean regions are depopulated, save by the few land 

 birds that can find subsistence, the closing of the sea forcing 

 water birds southward. As the supply of food is shorter in 

 winter than in summer there is depletion through migration 

 even in as hardy a species as the Snowy Owl. What transpires 

 in Arctic i"egions also occurs in a lesser degree far to the south- 

 ward. In the colder portions of the United States there is like- 

 wise the total migration of some species of the breeding season 

 and the partial migration of others. Besides, there is the occu- 

 pation of the territory evacuated by the birds that come from 

 further north, that find food where insectivorous species would 

 probably perish for lack of it, if not from cold. Upon the whole 

 the aggregate of birds is greatly diminished. Further south, as 

 in upper South Carolina, bird life is as abundant in winter as in 

 summer, but the character is changed, insectivorous species, 

 especially, giving place to those that are not dependent upon 

 insects for food. The infrequency of snow in this region makes 

 possible the presence of species in great abundance that occur 

 only in limited numbers further north. As is the case to the 

 northward, numerous resident species are less plentiful in winter 

 than in summer. It should be observed that a species may be 

 resident in the Middle States, or even further north, and yet be 

 less numerous in the Piedmont Region of South Carolina in 

 winter than in summer, there being migration at the South as 



