246 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



Late and early hatched birds laid at approximately the same time the 

 following spring." 



Plumages. — Mr. Smith (1937) describes the natal down as "dark 

 mouse gray." The young bird is in practically full juvenal plumage 

 when it leaves the nest, except for the short tail. The two sexes are 

 distinguishable in this plumage by minor differences. Dr. Dwight 

 (1900) describes the juvenal plumage of the yoimg male bluebird, as 

 follows: "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 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. Auricu- 

 lars dusky mouse-gray mixed with white; lores grayish; conspicuous 

 orbital ring pure white." 



The young female is similar to the juvenal male, except that "the 

 outer primary and outer rectrix have white outer webs, the blue is 

 everywhere very much duller, and replaced with brown on the terti- 

 aries and wing coverts, the edgings duller and the quills with duskier 

 tips." 



The first winter plumage is acquired by a partial postjuvenal molt, 

 in August and September, the date depending somewhat on the date 

 of hatching. This molt "involves the body plumage, wing coverts, 

 tertiaries and tail, but not the rest of the remiges." This plumage is 

 almost indistinguishable from the winter plumage of the adult male, 

 though the colors are somewhat duller; Ridgway (1907) describes it 

 very well, as follows: "Similar to the spring and summer plumage, 

 but blue of upper parts slightly duller, more or less obscured on hind- 

 neck, back, and scapulars, by brownish tips to the feathers, and 

 cinnamon-rufous of chest, etc., more purplish or vinaceous in hue." 



Dr. Dwight (1900) says of the first winter female: "In first winter 

 plumage the blue is obscure and confined to the wings, tail and rump, 

 the back is dull grayish chestnut, grayer on the crown. The sides of 

 the head are gray and white mixed, the orbital ring white. Below, 

 the throat, breast and sides are reddish cinnamon, tingeing also the 

 grayish white chin; abdomen and crissum dull white." 



The adult and first nuptial plumages of both sexes are acquired by 

 wear, which removes the edgings and brightens the whole plumage. 

 The following postnuptial molt, beginning about the middle of 

 August, is complete. 



Food.— In its food habits, the bluebird is one of our most useful 

 birds. It does practically no harm to human interests and it destroys 



