18 



NORTH AMERICAN FAUNA 73 



sion by a variety of plants will result in a rapidly changing vegetational com- 

 munity. Areas of Old Field community are usually no larger than 16 ha; 

 most are 4 to 8 ha. 



Characteristic plant species associated with this habitat include a variety 

 of pioneer trees and shrubs, such as trembling aspen, box elder, staghorn 

 sumac, and flowering crab apple. Grasses and forbs associated with this 

 habitat include timothy, awnless bromegrass, Kentucky bluegrass, quack- 

 grass, big bluestem, Uttle bluestem, hoary alyssum, blue vervain, moth 

 mullein, yarrow, evening primrose, common milkweed, alfalfa, goat's beard, 

 sheep sorrel, daisy fleabane, noble goldenrod, and sharp-toothed goldenrod. 



Characteristic breeding birds associated with this habitat include Ameri- 

 can kestrel, mourning dove, eastern kingbird*, brown thrasher, eastern blue- 

 bird, golden-winged warbler, yellow warbler, eastern meadowlark, brown- 

 headed cowbird, indigo bunting, American goldfinch, rufous-sided towhee, 

 clay-colored sparrow*, field sparrow*, and song sparrow. 



Managed Grasslands 



Within the Valley, several thousand hectares of upland fields have been 

 acquired by State and Federal conservation agencies as wildUfe manage- 

 ment areas or Waterfowl Production Areas. These lands are usually agricul- 

 tural fields that have been taken out of production. Several different man- 

 agement techniques are used to develop extensive areas of grasses and forbs 

 to provide nesting habitat for a variety of wildUfe species. 



Characteristic plant species established on Managed Grassland areas 

 include intermediate wheatgrass, switchgrass, timothy, and brome grass. 

 After estabUshment of these grasses, a number of forbs invade the areas. 

 Several characteristic invaders include hoary alyssum, yarrow, blue vervain, 

 daisy fleabane, and sharp-toothed goldenrod. 



These estabUshed communities provide habitat for a variety of species 

 including American bittern, mallard, pintail, blue-winged teal, marsh hawk, 

 ring-necked pheasant, short-billed marsh wren, common yellowthroat, bobo- 

 link, eastern meadowlark, western meadowlark, red-winged blackbird, dick- 

 cissel, and savannah, grasshopper, Henslow's, vesper, and song sparrows. 



Residential Habitats 



Small towns and cities scattered throughout the Valley provide a diver- 

 sity of habitats for breeding birds. Intermixed with concrete buildings are 

 areas of hedgerows, row trees, tree groves, lawns, and parks. Diverse food 

 sources, ranging from feed mills and lawns to gardens and bird feeding sta- 

 tions, add to the vegetation available for breeding birds. 



Characteristic birds associated with Residential Habitats include rock 

 dove*, mourning dove, screech owl, common nighthawk*, chimney swift*, 

 downy woodpecker, purple martin*, blue jay, black-capped chickadee, white- 

 breasted nuthatch, house wren, gray catbird, brown thrasher, American 

 robin, starUng*, house sparrow*, northern oriole, common grackle, cardinal, 

 rose-breasted grosbeak, and American goldfinch. 



