2^0 DAVENPORT ACADP:mY OF SCIENCES. 



Dr. A. K. Fisher states: "The diet is probably more varied 

 than that of most birds of pre}' ... the writer in his field ex- 

 perience has never seen one attack a fowl, nor has he found the 

 remains of one in the stomachs of those examined. ... Of 220 

 stomachs examined, 3 contained poultry: 12, other birds; 102, 

 mice; 40, other mammals; 20, reptiles; 39, batracians; 92, insects: 

 16, spiders; 7, crawfish: i, earthworm; 2, offal; 3, fish; and 14 

 were empty" (Hawks and Owls of the IT. S., 62-70). 



Subgenus Tachytriorchis Kaup. 



147. (342). Ihitco s'a'ai)iso)ii Bonap. Swainson Hawk. 



The Swainson Hawk is probably the commonest Hawk in most 

 parts of the West, rarely coming east of the Mi.ssis.sippi. It is 

 fairly w^ell distributed over Iowa as a migrant and nests from the 

 central to the northern portions of the state. The Swainson 

 Hawk nests somewhat later than the Red-tail, — in the early part 

 of May in northern Iowa. The nest is built in the small rem- 

 nants of native groves, or moderately timbered tracts, and the 

 bird .seems quite careless about its concealment. Almost invari- 

 ably fresh sprigs of green leaves are found in nests containing 

 eggs. May 16, 1894, I found a pair occupying an old nest of the 

 preceding year, in an oak, about lift}' feet from the ground. The 

 nest contained three fresh eggs. A dead green snake about fif- 

 teen inches long hung on a limb about a foot below the nest. 

 One of the Hawks w^as sitting on a dead tree not far off, and the 

 other remained on the nest until I had climed up several feet. 

 May 14, 1895, I found two considerably incubated eggs; May 18, 

 1897, four fresh eggs (Hancock). May 4, 1897, found a nest just 

 completed, but the nest was destroyed after the eggs were laid, 

 and an entirely new nest was built near by which contained two 

 eggs on May 18 (Winnebago). 



Fisher describes the food as "extremely varied, but consists of 

 more insect matter than is usually the ca.se in birds of prey of this 

 ('■roup. . . . of 18 stomachs examined, 7 contained small mam- 

 mals: 8, in.sects; 3, reptiles; 3, batracians; and 3 empty. ... of 

 65 stomachs examined, 2 contained small birds; 15, mice; 13, 

 other mammals; 11, reptiles; 13, batracians; 30, insects; 2, earth- 

 worms: 4, crawfi.sh, and 7 were empty" (Hawks and Owls, 72). 



