OF EASTERN PENNSYLVANIA. 233 



period of incubation ranges from sixteen to seventeen days. 

 But a single brood is reared in a season. 



The young are objects of extraordinary solicitude by the 

 parents, \vho vie with each other in. rendering them the 

 greatest attention. Thev are voracious feeders, and severely 

 tax their parents t<. provide them with an abundance of suit- 

 able food. While one parent is abroad in quest of food, 

 the other remains at home to protect its inmates from dan- 

 gerous foes which may be prowling about. The food of the 

 young at first consists of the Mesh of birds which the par- 

 ents are able to capture ; but when they have attained con- 

 siderable size, the food is provided entire. At the age of 

 three or four weeks the young are able to leave the nest, 

 and receive their food while clinging to the branches of trees. 

 When almost six weeks old. they are able to hunt for them- 

 selves, but still consort with their parents for a week or two 

 longer, when they separate and repair to distinct roosting 

 quarters, at night. 



The eggs are nearly spherical, and pretty equally symmet- 

 rical at the extremities. The ground-color is white, with a 

 livid tinge, and is almost wholly obscured by irregular, 

 Variously-shaded brownish blotches, which sometimes form 

 a wreath about the center, or near the larger end. In some 

 cases, these spots are pretty evenly distributed, but change 

 remarkably in number, size, and pattern. The average 

 measurement is 1.44 bv 1.16 inches. 



Accipiter cooperii, Gray. 



The Chicken Hawk or Cooper's Hawk as this species is 

 commonly designated, has a wide distribution. It extends 

 from South Carolina to New Brunswick on the Atlantic, 

 from Texas to Saskatchewan in the inland regions, and from 

 California to Washington Territory on the Pacific coast. It 

 is particularly abundant in the Middle States where it breeds, 

 and also on the banks of the Potomac River. It has been 

 30 



