ACCIPITER COOPERI : COOPER S HAWK. I07 



November that the visitants move southward. The 

 birds pair in April, and lay the latter part of this month 

 or early in May. The nest is usually high in a tree, 

 preferably an evergreen, resembling that of a Crow ; the 

 birds usually build for themselves, but sometimes fit up 

 a Crow's nest, or the nest of some other Hawk, to suit 

 their purposes. They appear to be devoted and assidu- 

 ous progenitors, if the way they persist in their efforts, 

 under discouraging circumstances, be taken as any 

 criterion. More than one instance has been recorded 

 of their laying at least thrice, when their nest has been 

 repeatedly robbed. Three, four or five eggs may be 

 found in the nest. They measure from 1.80 by 1.55 to 

 2. 10 by 1.60 — figures showing the variation both in size 

 and shape — they average about 1.90 by 1.50. They 

 resemble those of the Marsh Hawk so closely as to be 

 not certainly distinguishable, but they are usually more 

 globular, and with a more granulated shell. The great- 

 est diameter is at or very near the middle ; difference in 

 shape of the two ends is rarely appreciable. They are 

 usually more uniform in color than those of most hawks, 

 normally resembling the pale, scarcely-marked examples 

 occasionally laid by most species. The ground-color is 

 a white, faintly tinted with pale bluish or greenish- 

 gray ; if marked, it is with faint, sometimes almost 

 obsolete, blotches of drab, liable to be overlooked with- 

 out close inspection ; only an occasional specimen is 

 found with decided, though still dull and sparse, mark- 

 ings of pale brown. 



