88 BIRDS OP PENNSYLVANIA. 



high tree (the bird instinctively seeking safety rather than any par- 

 ticular kind of a tree), and consists of sticks and twigs, resembling the 

 Crow's nest, though generally somewhat larger and more compactly 

 built. Period of incubation about three weeks. The eggs usually 

 number from two to four, more commonly three ; in one instance I 

 found six. Of some thirty sets before me, there is a great diversity of 

 markings. In shape, form and ground- work they are all alike, but in 

 markings quite different. They are about the size, or a little larger, 

 than the eggs of the domestic fowl ; of a broad, oval form, granulated ; 

 of a dusky-white color, very slightly inclined to blue in the fresh egg, 

 with one or more very large reddish brown blotches on the larger end, 

 interspersed with smaller ones, diminishing in size and number as they 

 approach the smaller end. This is the most common appearance of 

 the egg. I have taken from the same nest eggs handsomely blotched 

 and white, or dirty- white without any marks. I have selected four sets 

 for measurement : 



No. 1, long diameter, . . 2.30 ; short diameter, . . 1.85 

 " 2, <* " . . 2.15; " . . 1.80 



" 3, " . . 2.30; " " . 1.80 



tk 4, " " . . 2.30; " ' . . 1.80 



u During the courting season it is very noisy, sailing around in circles 

 with its mate, and filling the air with its shrill notes. Their mutual 

 attachment continues through life. They hunt in pairs. The male 

 not only assists in incubation, but supplies his mate with food. If 

 approached by the sportsman while sitting, if the nest is low and ex- 

 posed, the female will fly off very quietly and stealthily long before 

 the male arrives within shot, and alight at some distance. If the nest 

 is high up she will draw down her head, thinking herself perfectly 

 concealed and secure, while her tail invariably projects over the nest, 

 giving unmistakable evidence of its occupancy. They become attached 

 to a particular piece of woods, and will build near the same spot for 

 years, if not killed, and will even continue to build there for some 

 time if their eggs are annually taken, occasionally rebuilding an old 

 nest ; according to my observations they usually prefer a new one. 



FOOD. 



Dr. Wood says : u This species subsists mostly on small birds and 

 quadrupeds, now and then adding to their bill of fare a snake." Merriam 

 says : " I once took from the stomach of one of these hawks a snake 

 measuring twenty-two inches in length." Wilson informs us that he 

 has taken the fragments and whole carcasses of ten frogs of various 

 dimensions from the crop of a single individual. "If not successful 

 in obtaining a supply of frogs, it will eat the flesh of dead animals or 

 fowls, apparently with a good relish." Wood. 



