Perching Birds Marked With Blue. 
* 766. Bluebird (Sialza stalis). L.7. Ad. 3. Above, 
including wings and tail, bright blue; throat and breast 
rusty brown, belly whitish.. 4d. 9. Above grayer, 
below paler. In winter specimens of both sexes have 
upperparts tipped with rusty. Notes. Call, tur-wee, 
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 (S. s. aurea). 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 occidentalis). 
L.7. Ad. 3. Above bright blue,foreback with more or 
less rust-brown, but rarely wholly chestnut; throat 
blue, breast rust-brown, belly bluish gray. Ad. : 
Above grayish blue; rust on foreback faintly indicated; 
throat bluish gray, breast paler than in <j. Notes. 
cal 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.) 
4.767a. Chestnut-backed Bluebird (S. m. bairdt). 
Similar to No. 767, but foreback wholly rust-brown. 
Range.—Rocky Mountain region from Wyoming south into Mexico. 
767b. San Pedro Bluebird (S. m. anabdela). 
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. 3. Above beautiful cerulean blue, throat and 
breast paler, belly whitish. Winter specimens are 
more or less tipped with brownish. Ad. 9. 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. 
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