11 



ravines of the rapid tributary streams, while Turkey Vultures breed 

 among the rocks and congregate in numbers on the low sandy islands. 



The Interior Uplands. — The bird fauna just described as charac- 

 terizing the lowlands of south-eastern Pennsylvania extends also 

 along the valleys between the Blue Mountain and South Mountain, 

 and some of the species penetrate even farther, following the course 

 of the larger rivers, and lend a Carolinian tinge to the fauna of the 

 valleys lying to the north of the Blue Mountain. Generally speak- 

 ing, however, the Carolinian element is not nearly so strongly 

 marked in the valleys north of South Mountain and its eastern 

 spurs, nor in the higher ground forming the water-sheds between 

 the drainage of the Delaware, Schuylkill and Susquehanna. 



The first appearance of Alleghanian species, such as the Chestnut- 

 sided Warbler, and the increase in the numbers of species which are 

 more characteristic of the Alleghanian than of the Carolinian zone, 

 as, for instance, the Scarlet Tanager, Black and White Warbler, etc., 

 is noticeable on the Welsh Mountain and Copper Mine Ridge in Lan- 

 caster county, and also in the eastern continuation of South Moun- 

 tain between Reading and Easton. 



Tlie Appalachian District. — Between the Blue Mountain and the 

 main crest of the Alleghanies is a series of sharp mountain ridges, 

 cut and broken by river valleys, mainly those of the Susquehanna 

 and its tributaries. 



This region is Alleghanian in its fauna, and with it is to be con- 

 sidered the northwestern mountainous part of New Jersey. As has 

 already been said, a few Carolinian birds are to be found in some of 

 the valleys, especially the broad valley of the Susquehanna, but 

 generally speaking the region is truly Alleghanian and is character- 

 ized by the occurrence in summer of such species as the Chestnut- 

 sided Warbler, Purple Finch, Savanna Sparrow, Black-capped 

 Chickadee, etc., which are not known as breeders in the Carolinian 

 Belt. 



The Alleghany and Pocono Mountains. — On the main Alleghany 

 mountain, extending from Susquehanna to Lycoming county. Pa., 

 and thence southwards to Somerset county, on the plateau region 

 of north-central Pennsylvania and on the Pocono Mountain plateau, 

 which occupies the north-eastern corner of the State, there probably 

 existed a bird fauna almost the same as that of the Catskills in New 

 York, and decidedly Canadian in its affinities. 



Now, however, the rapid destruction of the primeval hemlock 



