OF EASTERN PENNSYLVANIA. 171 



is lined with a few dried grasses and feathers, although 

 instances are not unfrequently met with where the eggs are 

 deposited upon the bare bottom. In the latter places, a few 

 rude sticks constitute a framework which is lined with a few 

 fine grasses and feathers. It is deposited upon a stout timber 

 in a somewhat inaccessible part of the building. Nesting 

 ordinarily takes place early in March, although we have ob- 

 served newly-built nests in the latter part of February. 



Oviposition commences about the second w r eek of March. 

 The number of eggs laid, varies from three to four, very 

 rarely more. Mating is of short duration, and is attended 

 with but little ceremony. Very little affection is manifested 

 by the sexes towards each other, and in the part of the year 

 unoccupied by such duties, a bitter feeling of animosity 

 often prevails among them, which often breaks out into bitter 

 conflicts when they approach each other. As soon as the 

 eggs are laid, which, on the average, amount to one a day, the 

 female commences the trying duties of incubation. This task 

 devolves exclusively upon her, as we have never observed the 

 male in the vicinity of the nest during" the day-time. It is 

 true that the former occupies the nest while the day prevails. 

 But when she vacates it at night in quest of food, it is pos- 

 sible that her partner may relieve her during her temporary 

 absence. The period of incubation is about twenty-four 

 days. 



The young are fed by both parents, w r ho attend to their 

 demands with unwearied patience. Their appetites are so 

 rapacious that one or the other parent is compelled to for- 

 age even at mid-day. Their food consists of fragments of 

 small quadrupeds and birds, and the various insects, both 

 coleopterous and lepidopterous, which they are able to find 

 in their nocturnal raids. The young leave the nest when 

 they are about four weeks old, and conceal themselves among 

 the branches and foliage of trees. At this time they are 

 able to make short flights from branch to branch, and -are 

 still fed by. one or the other parent. During the day they 



