EASTERN AND CANADIAN CHIPPING SPARROWS 1175 



The postjuvenal molt begins when the bird is about thirty days old. The post- 

 juvenal molt thus must begin in late June and early July in young of normal first 

 broods * * *. 



The plumage worn by the eight-day-old Chipping Sparrow is not, strictly 

 speaking, a complete plumage of any sort. Not until the bird is about three 

 weeks old docs it don its first set of lesser wing coverts. As the total skin area of 

 the growing bird increases new rows or sets of feathers appear, particularly in the 

 region of the lower breast and belly. 



The Juvenal middle and greater coverts drop out almost simultaneously when 

 the bird is about six weeks old. Molting of the body plumage takes place much 

 more gradually, but the streaked feathers of the under parts are all gone by the 

 time the bird is forty-five days old. 



The postjuvenal molt does not involve the remiges and rectrices, but it does 

 involve the tertials, the dropping out of which is subsequent to that of the middle 

 and greater coverts. 



The plumage acquired by this partial molt is the first winter plum- 

 age which Dwight (1900) describes as similar to the juvenal plumage 

 "but ^vith the chestnut crown veiled with buff edgings and narrowly 

 streaked with black. Below, uniform grayish white, unstreaked, 

 washed with buff on throat and sides. Supercihary line dull white 

 buff tinged. Loral, postocular and indistinct submalar streaks 

 black." 



The first nuptial plumage is acquired by a molt in March and April 

 confined largely to the head, chin, and throat. This results in the 

 chestnut crown, the white superciliary fines and the white chin with 

 the adjacent cinereous gray characteristic of the adults (Dwight, 

 1900). Other changes involve increased streaking of the back brought 

 about by abrasion and a general pafing of the buff and chestnut 

 caused by gradual fading. 



Adult winter plumage is acquired by a complete postnuptial molt, 

 and the adult nuptial plumage by a partial prenuptial molt (Dwight, 

 1900). 



Food. — Judd (1900) examined the contents of 250 stomachs taken 

 from March through November from New England to California. 

 He found that for the whole sample the food was 62 percent vegetable 

 and 38 percent animal. The vegetable component was made up 

 largely of grass seed (48 percent of total food) which included 26 

 percent (of total) crab and pigeon grass seed; the rest was grain 

 (4 percent) and a miscellany (10 percent of total) of the seeds of clover, 

 ragweed, amaranth, wood sorrel, lambsquarters, purslane, chickweed, 

 knot weed, and black bindweed. The animal component contained 

 weevils (6 percent), leaf beetles (2 percent), other Coleoptera (3 per- 

 cent), caterpillars (9 percent), grasshoppers (10 percent), and 8 percent 

 made up of such organisms as leafhoppers, true bugs, ants, spiders, and 

 parasitic wasps. He found that in June the food was 93 percent 



