1280 U.S. NATIONAL MUSEUM BULLETIN 237 part s 



5th day, and the male responds to their trilling only after the 7th day. 

 In 1957 I noted: 



"It is surprising to see how well the pale lining of the female's feather- 

 ing causes her to blend inobstrusively with the straw border of the 

 nest as she broods. The young grow so quickly that on the third day 

 they push up the female, beg, and gape without parental provocation. 

 They nestle deeply into the nest when the sun dips in late afternoon. 

 On the fourth day their eyes are open during shady intervals, and fully 

 open the next day. They hug the nest when the female scolds and 

 no longer gape at my touch. The tail feathers are now one quarter 

 inch long." 



"By the seventh day the female has trouble brooding sio.ce the 

 young toss and turn. The next day they scratch and preen for the 

 first time, and anticipate the parent's return by trilling." 



Feeding and nest-sanitation are shared almost equally by the 

 parents, the male making slightly more than half the feedings, and 

 removing slightly more than half the fecal sacs. Usually the old 

 birds carry the fecal sacs away, but they occasionally eat the small 

 ones. On their 8th day the young receive feeding visits on an average 

 of one every 10 minutes. On the 9th day they will leave the nest if 

 disturbed, but probably stay on another day or two when not pressed. 



Plumages. — One-day-old young are fluffy in mouse-gray natal down 

 which covers capital, dorsal, alar, and femoral tracts, but not the 

 ventral tract. 



My Labrador notes contain a description of a fledgling about 2 days 

 off the nest. It had dark brown eyes, the bill was brown, and the 

 gape and most of the commissure corn-yellow, the tarsus lilac, and 

 the toenails light horn gray. Francis Harper (1958) describes a young 

 bird as having vermillion mouth linings, with commissure and tomia 

 corn-yellow. 



Richard R. Graber (1955) describes in detail the juvenal plumage 

 on the basis of a bird from Colorado and another from Labrador: 



"Forehead and crown streaked throughout with black. Crown and 

 forehead white medially, brown laterally. Occiput dark, mottled 

 brown and black. Nape mottled, white and black. Back streaked, 

 black and buff. Rump and upper tail coverts rusty-buff, streaked 

 with black. Rectrices and remiges black. Primaries edged with buff, 

 secondaries and tertials with dull rust color. Uppermost (proximal) 

 tertials edged and tipped with buffy white. Lesser coverts gray; 

 medians black, edged with white; greater coverts black, edged with 

 buff, tipped with white. Two white wing bars. Lores dark, brownish 

 or gray. Narrow white supra-ocular stripe from eye to nape. Auric- 

 ulars buff-tinged gray, post-auriculars like nape. Chin and throat 

 white, flecked with black, and with black "mustache" marks. Under 



