316 DWIGHT 



Female. — The moults and plumages correspond to those of 

 the male, the plumages duller, and the prenuptial moult often 

 limited in extent. The transocular line is obscure in first winter 

 dress, and dull black in subsequent plumages. 



Sialia sialis (Linn.). Bluebird 



1. Natal Down. No specimen seen. 



2. Juvenal Plumage acquired by a complete postnatal moult. 



Above, slaty mouse-gray, the back lesser, median and a few inner greater coverts 

 with white guttate spots bordered with sepia, the crown and rump much grayer 

 and unspotted but sometimes with obscure dusky transverse barring. Wings 

 and tail dull azure-blue, the shafts and tips of remiges and rectrices dusky with 

 faint whitish edgings ; tertiaries and greater coverts edged with pale chestnut. 

 Below, dull white, mottled on throat, breast and sides with sepia, the feathers 

 centrally white bordered by the sepia and a rusty suffusion. Auriculars dusky 

 mouse-gray mixed with white ; lores grayish ; conspicuous orbital ring pure 

 white. Bill and feet dusky pinkish buff becoming deep sepia. Virst primary 

 and outer pair of tectrices without the white edging of the female. 



3. First Winter Plumage acquired by a partial postjuvenal 

 moult, in August and September, which involves the body 

 plumage, wing coverts, tertiaries and tail, but not the rest of the 

 remiges. 



Unlike the previous plumage and wholly blue and chestnut. Above, including sides 

 of head, orbital ring and wing coverts, deep azure or purplish cobalt-blue, often 

 campanula-blue on the crown, veiled everywhere with pale chestnut edgings, 

 the tertiaries and wing coverts faintly whitish edged. Below, pale chestnut, 

 white on abdomen and crissum. the anterior part and sides of the chin dull 

 white mixed with a little blue. Tail brighter blue than in juvenal plumage, 

 the rectrices without dusky tips or whitish edgings. 



4. First Nuptial Plumage acquired by wear, through 

 which the edgings of the back are lost and the color becomes an 

 ultramarine or azure blue depending somewhat upon the angle 

 at which the light strikes the plumage. The chestnut below 

 fades. 



5. Adult Winter Plumage acquired by a complete post- 

 nuptial moult beginning about the middle of August. Practi- 

 cally indistinguishale from first winter dress, the colors usually 

 somewhat richer and the chin bluer. 



