l5o SUMMER BIRDS. 



ran^e. the discovery of its beincr a regfular inhabitant of the Catskill 

 Mountains would have been a matter of greater surprise. Though 

 the Catskill region is not forty miles north of the Highlands of the 

 Hudson where the Large-billed Water Thrush has been characterized 

 as a common summer resident by Dr. E. A. Mearns.'" it was scarcely 

 to be expected that a species regarded as of distinctly Carolinian 

 relationship would be found in the character of a regular summer 

 resident under conditions congenial to other species pertaining to 

 a sub-fauna two removes northward. The seeming incongruity is 

 especially striking when we consider that not only do none of its 

 associates in the Hudson \'alley. which with it there constitute the 

 decided southern element of the Avi-fauna, enter this region, but 

 several AUeghanian forms (already specified) seem to be completely 

 barred out, while others are much restricted in their entrance. As 

 explanatory of these facts are to be entertained the distinctive traits 

 of the species under consideration. Its preferences are decidedly, 

 at least Eastward, for active shaded water-courses, with rocky and 

 deeply worn beds ; and it can easily be conceived how an inherent 

 trait of ascending toward head- waters in search of these conditions 

 might result in the continuance of a slight deviation from its usual 

 range into a more or less extended journey. Thus may strong 

 specific traits result as primary factors in distribution. In the case 

 before us. unless the bird be of less southern relationship than has 

 been supposed, this apparent innovation in the recognized rules of 

 the distribution of a species would seem to arise from the subor- 

 dination of physical regulations to specific characteristics and prefer- 

 ences. There are many localities in the Catskills admirably adapted 

 to the requirements of this bird — that is, in so far as appearances 

 permit judgment — and which unoccupied by it would suggest a vac- 

 cuum in nature. 



There are birds adapted to the man\- characteristic features of 

 mountains and valleys, but the mountain torrents but for this species 

 would be left unavailed. We have, indeed, in the Large-billed Water 

 Thrush, our closest Eastern representative of our Cindus of the West. 



The apparent absence in the Adirondacks of any bird specially 

 adapted to the mountain water-courses seems like a deficiency in the 

 life of the region; and now that this species has been found on the 

 borders of that " Canadian Island," it may not be too far in the region 

 of speculation to anticipate a time when we shall learn of it as a true 

 summer resident there. 



Among the Catskill Mountains it appeared to be perfectly at home. 

 At the head of the Big Indian Valley, along the Esopus, the louder 



* Bull. Essex Inst., XI, 159. 



