ORNITHOLOGY 



PART I 



PHYSICAL FEATURES, HABITATS, BIOGRAPHICAL 

 NOTES AND REVIEW OF FAUNAL LISTS 



Chester county lies in the southeastern part of 

 Pennsylvania, bordering the states of Delaware and 

 Maryland from the Brandywine to the Octoraro, 

 and extends northward to about 40° 15' on the 

 Schuylkill. With the exception of the extreme 

 southeastern townships, its area of 780 square miles 

 is a part of the Delaware river system. Chester val- 

 ley cuts through the centre in a southwesterly direc- 

 tion at a depth varying from 200 to 400 feet, and 

 from 500 to 2,000 yards wide for practically the 

 entire distance of 30 miles; dividing the county 

 in not unequal parts. For almost two hundred years 

 this valley has been almost entirely deforested and 

 under cultivation ; in consequence its wild animal 

 life is less varied than that of the wooded hills on 

 either side. It would appear, however, that the 

 Killdeer, Red-headed Woodpecker and Grasshop- 

 per Sparrow are more constant breeders here than 

 elsewhere in the county, and the Mallard and Black- 

 crowned Night Heron are peculiar to the broad and 

 deep eastern part. 



The northern half of the county is a succession 

 of hills and vales to the Welsh mountain (elevation 

 728 feet above the sea at Waynesburg). From the 

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