TURDID.E—TURDINjE: BLUEBIRDS. 257 



Gape ample ; rictus cleft to below eyes, furnished with a moderately developed set of bristles 

 reaciiing about opposite nostrils. Feet short, rather stout, adapted exclusively for perching 

 (in Saxicola the structure uf the feet indicates terrestrial habits). Tarsus not longer than middle 

 toe ; lateral toes of unequal lengths ; claws all strongly curved. Blue is the principal color of 

 this beautiful genus, which contains 3 species and several subspecies. They are strictly arbori- 

 cole ; frequent the skirts of woods, coppices, waysides, and weedy fields ; nest in holes, and lay 

 whole-colored eggs; readily become semi-domesticated; feed upon insects and berries; and 

 have a melodious warbling song. Polygamy is sometimes practised by them, contrary to the 

 rule among Oscincs. Bluebirds are peculiar to America, and appear to have no exact repre- 

 sentatives in the other hemisphere. 



Analysis of Species. 



(f Rich sky-blue, uniform on back ; throat and breast chestnut ; belly white sialis 



(f Rich sky-blue, including throat ; iliiddle of back and breast chestnut ; belly whitish mexicana 



cf Light blue, paler below, fading to white on beUy ; no chestnut arctica 



S. si'alis. (Gr. o-taXt'f, «/«?/*, a kind of bird. Fig. 122.) Eastern Bluebird. Wilson's 

 Bluebird. Blue Robin. (J, in full plumage : Rich azure-blue ; ends of wing-quills black- 

 ish ; throat, breast, and sides of body chestnut ; belly and 

 cri.ssum white or bluish-white. The blue sometimes ex- 

 tends around the head on sides and fore part of chin, so that ~'^'%y .^^*^^^^^J 

 the chestnut is cut off from bill. Length 6.50-7.00; ex- '^^^ ~Z'^^ v-i««ss 

 tent 12.00-13.00; wing 3.75-4.00; tail 2.75-3.00; bill "-^'f |^V'''*^^ 

 0.45; tarsus 0.70. ^, in winter, or when not full-plu- 

 maged : Blue of upper parts interrupted by reddish-brown 

 edging of the feathers, or obscured by a general brownish 

 wash. White of belly more extended ; tone of other under 

 parts paler. In many Eastern specimens, the reddish-brown ^^^^!2Ss 

 skirting of the feathers blends into a dorsal patch; when '<r^^ 

 tliis is accompanied by more than ordinary extension of 

 blue on throat they closely resemble S. mexicana. 9 , in ' p^^ 122. -Bluebird, nat. size. (Ad 

 full plumage: Blue mixed and obscured with dull reddish- nat. del. E. c-) 



brown ; becoming bright and pure on rump, tail, and wings. Under parts paler and more 

 rusty-brown, with more abdominal w^iite than in $. Little smaller than $. Young, newly 

 fledged : Brown, becoming blue on wings and tail; back sharply marked with whitish shaft- 

 lines. Nearly all the under parts closely and uniformly freckled with white and brownish. 

 A white ring r()und eye ; inner secondaries edged with brown. From this stage, in which the 

 sexes are indistinguishable, to the perfectly adult condition, the bird changes by insensible 

 degrees. Eastern U. S. and Canada ; abundant and familiar, almost domestic ; W. often to 

 the Rocky Mts. Migratory, but breeds throughout its range, wintering in tlu- iMiildle States 

 and beyond, whence it comes as one of the early harbingers of spring, or during mild •winter 

 weatlier, bringing its bit of blue sky with cheery, voluble song. Nest in natural or artificial 

 hollows of trees, posts, or bird-boxes, loosely constructed of the most miscellaneous materials; 

 <'ggs 4-0, pale bluish, occasionally whitish, unmarked, 0.80X0.60; two or three broods in 

 one season. 



S. s. azu'rea. (New Lat. adj. azureu!^., azure, sky-blue; Middle Lat. noun ozitra, azuruni, 

 lazur, lazurius, lazulus, a blue stone, the Icqns lazuli, Gr. \aCovpiov, Inznurion, from Arabic 

 lazward; Persian lazhward; said to be named from the mines of Lajwunl.) Azure Blue- 

 bird. Similar to S. sialis ; the blue of a greenish .shade; breast paler chestnut; crissum 

 buffy ; tail about 3.00. S. Arizona and southward. A slight variety, first described by Baird, 

 Rev. Am. Birds, 1804, p. 62 ; taken into Key, 3d ed., 1887, p. S66 ; A. O. U. List, No. 766 a 

 (wrongly accredited to SwAlxsox, and the date of Baird's Review misprinted 1884). 



17 



