FAUNAL POSITION. 
139 
istic Canadian birds undoubtedly never occur. But these are non- 
migratory species, and it becomes plain, with this fact in view, that 
the limited extent and isolation of the Catskill region renders their 
absence in the face of favorable conditions easily explicable. The 
higher mountain Fauna of the Catskills may therefore be regarded 
as purely Canadian in character. 
Between those altitudes where these simplified faunal conditions 
prevail and the lower valleys, we may trace the two approximating 
Faunae in every degree of union. The result is that we find species 
of totally different distributional relationship occupying the same 
ground. This is easily illustrated : While such species as the Win- 
ter Wren, Black-throated Blue, Black-and- Yellow, Mourning, and 
Canadian Fly-catching Warblers, Blue-headed Vireo, and Slate-col- 
ored Snowbird, occur certainly as low down as i, 5 oo -1,600 feet, 
species of much more southern distribution, as the Chewink, Field 
Sparrow, House Wren, Wood Thrush, Indigo Bird, Large billed 
Water Thrush, and Bluebird (named approximately in the order of 
their altitudinal limitation from below upward) extend to an altitude 
of from 2,000 to perhaps 2,5oo feet. 
Further details regarding the local distribution of species appears 
in the following review of the birds, in which, with respect to a very 
limited portion (already defined, page 117) of the great Appalachian 
Mountain system, the facts regarding the summer Avi fauna will, so 
far as brief but continuous and careful observation could discover 
them, be presented. 
As has already been said, the geographical scope of the present 
paper is restricted to the southern Catskills. But as this section of 
the region can claim the highest of the mountains, it seems probable 
that few if any birds ot the Canadian Fauna are regular summer 
residents in the northern Catskills which do not also occur in the 
southern. 
Unless otherwise stated, all references to the region are to the Big 
Indian Valley and the adjoining mountain slopes in Ulster County, 
the whole section being included in the township of Shandaken. 
