^"s ' X H Loomis on Birds of Chester County, South Carolina. £*J 



been no visible failure of food in this locality. The winter 

 migratory movements of the Robin prove that a host may find 

 ready subsistence where few or none have been previously sojourn- 

 ing. It is evident that abundance of food alone does not insure 

 presence. When limited in numbers only a small area can be 

 thickly inhabited, no matter how inviting the surrounding region 

 may be. As some place must be selected when birds are not 

 sufficiently abundant to populate the whole region temporarily 

 available for residence, choice is made, though it may be a tem- 

 porary one, as is the case in the Red-winged Blackbird here 

 locally in winter, or it may be more permanent, as in the Robin, 

 here in summer, or, in a smaller way, as in the Prairie Horned 

 Lark (Auk, VIII, pp. 57, 5S). Below the territory where 

 snow is frequent, there must be wide opportunity for selection, 

 but where the ground is covered for a long time, only such places 

 as afford food on trees, etc., can be inhabited. 



The absence of the Red-headed Woodpecker in Lewis County 

 in northeastern New York (Merriam, B. N. O. C, III, 

 p. 124) in winters when there were no beechnuts left on the 

 trees, is a circumstance bearing directly upon this point. That 

 this Woodpecker should winter in numbers, locally, in New 

 York, even in the severest seasons, and in Vermont (Knowlton, 

 B. N. O. C, VII, p. 63), and be absent here from October 

 to April for successive years, may seem singular. In the 

 abandonment of this locality in winter, however, it does not 

 present any different feature than is exhibited in the Robin. 

 The literature abounds in references to the erratic distribution 

 and movements of this Woodpecker. The explanation appears 

 simple. It is a bird that is distributed in isolated communities, 

 and the communities vary in location, in the adjustment locali- 

 ties remaining untenanted for a varying period. Its absence 

 in this vicinity in winter is understood to signify that the summer 

 residents have departed, that the migrants have passed on, and 

 that winter birds have centred elsewhere. Scarcity or abun- 

 dance in summer is explained by shifting of position of breeding 

 communities, and in the height of migration, by variation of 

 lines of movement. 



With the exception of the Dickcissel, the irregular breeding 

 and winter birds mentioned above have been of habitual occur- 



