SUMMER BIRDS. 
I 5o 
range, the discovery of its being a regular 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 Valley, 'which with it there constitute the 
decided southern element of the Avi-fauna, enter this region, but 
several Alleghanian 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 many 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 Cinclus 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. 
