NESTING-SITES. 87 



in blufifs, and often an old Hawk's or Crow's nest is occupied. 

 The Short-eared Owl usually nests on the ground. 



Hawks usually build their nests of coarse sticks and twigs, 

 placing them in high trees. The nest of the Sparrow Hawk is 

 placed in the cavity of a high tree, while that of the Marsh Hawk 

 is usually placed on the ground. Hawks and Owls breed as early 

 as February and March. 



All the nests of the Carolina Dove which I have found on the 

 ground in Central Ohio', where the soil is clayey and cold, the eggs 

 were often addled, and this applies to other partially ground-nest- 

 ing birds, such as the Brown Thrasher. 



Ruby-throated Hummingbirds and Nest. 



I have observed that in Ohio the Ruby-throated Hummingbird 

 prefers nesting in the branches of the buckeye to all other trees. 

 The birds are especially abundant about this tree when it is in full 

 blossom, early in May. In other localities they are found nesting 

 on the horizontal limb of a forest tree, or in an orchard. Careful 

 and patient observation of the birds themselves during the breed- 

 ing season gives the best clue to the situation of nests, many of 

 which are hidden with the utmost display of the instinct of self- 

 preservation. 



Eggs, as a rule, should be kept in sets; a "set" being those 

 taken from any one nest ; and each one of a set should bear a num- 

 ber referring to a corresponding one in a note-book where full par- 



