FIELD COLOR KEY 



2'. Upper parts purplish blue, black 

 ring around head and neck ; 

 wings and tail bright blue, 

 barred with black and marked 

 with white. Imitates cries of 

 Hawks. 



p. 154. BLUE JAY. 



1'. SMALL ; HEAD NOT CRESTED. 

 3- Body wholly blue or blue-black. 



4. Shining blue-black ... p. 48. PURPLE MARTIN. 



4'. Ultramarine to cerulean blue and green. 



p. 149. INDIGO BUNTING. 



3'. Body not wholly blue or blue-black. 



5. Under parts reddish brown. 



6. Upper parts steel-blue ; tail 

 deeply forked ; forehead chest- 

 nut. Often seen skimming low 

 over meadows for insects. 



p. 49. 



BARN SWALLOW. 



6'. Upper parts intense blue ; tail not forked ; forehead 

 blue like back. p. 41. BLUEBIRD. 



5'. Under parts not reddish brown. 

 7. Under parts white throughout ; back 

 steel-blue. Nests in trees or in bird- 

 boxes. 



p. 194. TREE SWALLOW. 



7'. Under parts not white throughout ; back grayish 

 blue. 



