146 HOW TO STUDY BIRDS 



shouldered hawk and the long-eared, screech, and 

 saw-whet owls. About May tenth Is the time for 

 Cooper's, marsh, broad-winged, fish, and sparrow 

 hawks, and a week or two later the sharp-shin brings 

 up the rear. 



Most of the hawks nest In tall trees In the woods, 

 building a rather rude platform of sticks In a main 

 crotch, or taking and repairing some old nest of crow, 

 squirrel, or another hawk. The exceptions are the 

 sparrow hawk, which lays In a hollow tree on or bor- 

 dering open land, and the marsh hawk which builds 

 a rude nest on the ground in a swamp. Most of the 

 owls use hollow trees or other cavities, but the great 

 horned and barred owls are just as apt to appreciate 

 an old open nest of hawk, squirrel, or crow, though 

 they often use hollows. The long-eared owl habit- 

 ually uses an open nest In the woods, and the short- 

 eared nests on the ground In a swampy place, among 

 grass and weeds, or under a bush. 



The special hunt for the nests of hawks and owls Is 

 a fascinating piece of work. In preparation for It, 

 a good plan Is to previously explore the woodland 

 tracts throughout the section of country to be in- 

 vestigated, during the preceding autumn and winter. 

 The nests are large and conspicuous, and are fre- 

 quently used again and again, either by the same bird 

 each year, or by different pairs of raptorial birds, or 

 else a pair occupies each of several nests In rotation 

 year by year. If an old nest is not reoccupled, an- 

 other may be built near it. Most of the species are 



