"2/1 Loomis, Summer Birds of Pickens County. S. C. f January 



Carolina, give peculiar emphasis to the fact that a single locality 

 cannot safely be accepted as a criterion in the determination of 

 vertical distribution, local conditions — not always obvious — 

 often exercising greater influence than does mere elevation. The 

 rigid adherence of Seiurus aurocafiillus to the belt above 2000 

 feet — a circumstance naturally not to be expected, if altitude were 

 absolutely paramount, of a species occurring within the bounds 

 of the Carolinian Fauna — strongly contrasts with the wide ranging 

 of Dcndroica vtrens. The uniform allotment of Helmitherus 

 ver?m'vorus, Seiurus motacilla, Geothlypis fortnosa, Thryo- 

 thorus ludovicianus , Parus bicolor, Parus carolinensis, shows 

 what little weight height actually has in these mountains in gov- 

 erning the upward range of some of the characteristic components 

 of the Carolinian fauna. Of species whose range seems definitely 

 restrained by altitude, it would naturally be expected that there 

 would be a gradual diminution in abundance in receding from 

 base or summit, but this is not strictly the case — the highest and 

 lowest points often exhibiting, in a given area, numbers not un- 

 equal. The pushing up along the barren ridges of Sitta pusilla 

 of the Louisianian fauna strikingly illustrates the force exerted by 

 floral surroundings. It should be added, further, that the streams 

 of larger size are apparently as influential in extending the altitu- 

 dinal range, in certain instances, as are rivers the latitudinal. 

 The north fork of the Oolenoy well exemplifies this, the extreme 

 limits, so far as noted, of a number of species being attained on 

 this water-course near the High-low Gap. 



To summarize, while the predominant factor in the constitution 

 of the bird-fauna of these mountains is altitude, still it does not 

 strictly control vertical distribution, its immediate force being 

 modified, 



1 . By the combined effect of the mountains, this collective in- 

 fluence pervading the lower grounds to such a degree as to check 

 the extension of the more susceptible Carolinian forms and to 

 'ncrease that of some Alleghanian. 



2. By the flora, conditions of this nature — often of great 

 potency whei - e local habitat is concerned — extending or curtailing 

 the general range. 



3. By streams (natural highways encouraging extension of 

 range) and other surface features, upon which depends the pies- 



