76 FIELD KEY TO COMMON BIRDS. 



It should be borne in mind that living birds do not 

 look as long as they really are. The measurement of 

 "length" is taken with the bird's neck and tail out- 

 stretched in a straight line. In life the tail may be raised 

 or drooped, while the neck is drawn in or curved, making 

 the bird look shorter than measurement shows it to be. 

 Remember that the Robin measures ten inches, the House 

 Sparrow six and one-fourth inches, and the Ruby-throated 

 Humming-bird three and three-fourths inches in length, 

 and you will have a basis for comparison. 



FIRST GROUP. 



BIRDS THAT FEED ON THE WING FOR LONG INTERVALS OF TIME 

 WITHOUT PERCHING. 



(Swallows, Swift, Nighthawk, Whip-poor-will.) 

 I. Size large, length over 9-00 inches ; the spread wings over IS'OO 

 inches in extent ; generally seen only late in the afternoon or at 

 dusk. 



1. A bird of the air, flying high, often over housetops in cities ; a conspicu- 

 ous white spot in each wing ; note, a loud, nasal peent ; sometimes dives 

 earthward with a booming sound ; May to Oct. . NIGHTHAWK, page 144. 



2. Haunts, near the ground, not often observed while feeding; call, given 

 from a rock, stump, or similar perch, whip-poor-will, vigorously repeated ; 

 Apl. 25 to Oct WHIP-POOR-WILL, page 146. 



II. Size smaller, length under 9'00 inches ; the spread wings less than 

 15'00 inches in extent ; may be seen at any time of the day. 



1. Plumage entirely black. 



a. Length 5-50 inches ; plumage sooty black ; usually nests in chimneys ; 

 Apl. 25 to Oct CHIMNEY SWIFT, page 146. 



b. Length 8-00 inches; glossy, bluish black; nests in gourds or houses 

 erected for its use ; Apl. 25 to Sept. . . . PURPLE MARTIN, page 216. 



2. Plumage not entirely black ; Apl. to Oct. . SWALLOWS, pages 214, 215. 



SECOND GROUP. 



CLIMBING AND CREEPING BIRDS. 



(Nuthatches, Creepers, Woodpeckers?) 

 I. Birds without stiffly pointed tail-feathers, that climb either up or 



down. 



1. Length 6*00 inches; back gray, cap black, cheeks and under parts 

 white ; note, a nasal yank, yank ; a permanent resident. 



WHITE-BREASTED NUTHATCH, page 250. 



