KEY TO BIRDS' NESTS 



BBB. Larger, over 2 inches deep inside. 



1. Of dried grasses, sometimes 



partially supported 



Orchard Oriole 



2. Of fibers, strings, and the like. 



Baltimore Oriole 



IV. In Holes in Trees or in Bird-Boxes. 



A. Nesting in colonies Purple Martin 



AA. Nesting singly. 



B. Drilling holes, no nest at bottom. 



1. Opening about 1J4 inches. . . . 



Downy Woodpecker 



2. Opening about 1% inches 



Hairy Woodpecker 



3. Opening about 2 inches 



Red-headed Woodpecker 



4. Opening over 2 inches Flicker 



BB. Using old Woodpecker holes or natural 



cavities of the same size or bird- 

 houses with similar openings, build- 

 ing a nest at bottom of cavity. 



1. Nest of sticks lined with feath- 



ers House Wren 



2. Nest entirely of grasses . . . Bluebird 



3. Nest of straws and feathers. 



a. Nest cup-like, open above. 



Tree Swallow 



b. Nest spherical or partially 



arched 



House (English) Sparrow 



4. Nest of fibers, moss, wool, and 



feathers . . Chickadee and Nuthatch 



5. Nest usually containing a cast 



snake-skin Crested Flycatcher 



BBB. Using Flicker holes or natural cavities 



of similar size, no nest built 



Sparrow Hawk, Screech Owl, and 

 Saw-whet Owl 



BBBB. Using larger natural cavities 



Barred Owl, Great-horned Owl, and 



Wood Duck 



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