Perching Birds Marked With Blue. 



766. Bluebird( Sialia sialis ) . L . 7. Ad. $ . Above, 

 including wings and tail, bright blue; throat and breast 

 rusty brown, belly whitish. Ad. 9. Above grayer, 

 below paler. In winter specimens of both sexes have 

 upperparts tipped with rusty. Notes. Call, tur-wee y 

 tur-wee\ song, a rich and sweet but short warble. 



Range. — Eastern United States; breeds from the Gulf States to 

 Nova Scotia and Manitoba; winters from southern New England and 

 southern Illinois southward 



766a. Azure Bluebird (5. 5. a^urea). Similar to 

 No. 766, but breast paler, upperparts less deep, more 

 cerulean. 



Range. — Mountains of eastern Mexico north to southern Arizona. 



767. Western Bluebird (Sialia mexicana Occident alis) . 

 L. 7. Ad. c^. Above bright blue, foreback with more or 

 less rust-brown, but rarely wholly chestnut; throat 

 Hue, breast rust-brown, belly bluish gray. Ad. ?. 

 Above grayish blue; rust on foreback faintly indicated; 

 throat bluish gray, breast paler than in rj". Notes. 

 Call, suggests that of No. 766, but is louder and 

 wilder. 



Range. — Pacific coast region from northern Lower California north 

 to British Columbia, east to western Nevada and casually, during mi- 

 grations, to New Mexico. (Ridgway.) 



767a. Chestnut-backed Bluebird (S. m. bairdi). 

 Similar to No. 767, but foreback wholly rust-brown. 



Range. — Rocky Mountain region from Wyoming south into Mexico. 



767b. San Pedro Bluebird (5. m. anabelce). 

 Rust-brown of back and breast greatly reduced in ex- 

 tent, usually wholly wanting or barely indicated on 

 back, and divided into two patches on breast by back- 

 ward extension of blue of throat; W. 4-2. (Ridgw.) 



Range. — San Pedro Martir Mountains, Lower California. 



768. Mountain Bluebird {Sialia arctica). L. 7.5. 

 Ad. $. Above beautiful cerulean blue, throat and 

 breast paler, belly whitish. Winter specimens are 

 more or less tipped with brownish. Ad. $. Above 

 brownish gray, rump blue, throat and breast gray- 

 ish buff; belly whitish. Notes. Call, suggests that 

 of No. 766, but in fall is merely a feeble chirp. 

 (Ridgw.) 



Range.— Western United States, except Pacific coast; breeds from 

 the Sierra Nevada east to the Plains and from New Mexico north to 

 the Great Slave Lake region; winters from the Mexico boundary 

 states south into Mexico. 



182 



