COAST BUSHTIT 445 



after nest-leaving. Feeding of the entire brood lasted nine days, after which one 

 or two individuals were fed at long intervals. 



Plumages. — The young bushtit is hatched naked, with eyes closed; 

 tiie eyes are not open until the eighth day or later, according to Mrs. 

 Addicott (1938). Mrs. Wheelock (1904) says that on the sixth day the 

 young were "covered with a hairlike grayish white down." This is very 

 scanty and is worn for only a short time, as the juvenal plumage soon 

 pushes it out, and the young bird is practically fully fledged when it 

 leaves the nest and is able to fly for a short distance. The juvenal 

 plumage is much like the faded and worn plumage of the spring and 

 summer adult; Mr. Swarth (1914) says that this plumage, "with shorter 

 and fluffier feathers, and with more extensively light-colored bases, gives 

 a general eilect that is rather mottled and uneven." This plumage is 

 worn for about 2 months, or until tov/ard the end of July, when the 

 postjuvenal molt begins and continues through September. This is an 

 incomplete molt, which does not involve the flight feathers; it produces 

 a first winter plumage which is practically indistinguishable from that of 

 the adult, dense and lustrous and dark colored. Adults have one com- 

 plete postnuptial molt each year at about the same time, but beginning a 

 little earlier in July and continuing a little later, or into October. Mr. 

 Swarth (1914) says that the molt is "of quite long duration, about 

 three months for adults, and a little less for the post-juvenal molt." 

 Considerable wear and fading take place during the winter and spring, 

 so that before the annual molt takes place the birds become quite dull in 

 coloration, worn, and shabby. 



Food. — Prof. F. E. L. Beal (1907) examined 353 stomachs of bush- 

 tits from California. He. says: 



The first analysis of the food of the year gives nearly 81 percent animal 

 matter, composed entirely of insects and spiders, to 19 percent of vegetable. * * * 

 The largest item in the insect portion of the bird's food consists of bugs (Hemip- 

 tera), which amount to over 44 percent of the whole. * * * Moreover, the 

 particular families of Hemiptera so extensively eaten by the bush tit are the two 

 that are most destructive to the interests of horticulture— namely, the plant-lice 

 (Aphididae), and bark-lice, or scales (Coccidae). The last amounts to nearly 19 

 percent of the year's food, and are eaten in every month. * ♦ * The large black 

 olive scale (Saissctia oleae) was identified in 44 stomachs, but other species were 

 also found. * * * While the San Jose scale was not positively determined [prob- 

 ably because its distinctive characters are too minute to be recognized in a mass 

 of semi-digested food], another species of the same genus, the greedy scale 

 (Aspidiotus rapax), was found in 4 stomachs, and scales not specifically identified 

 were found in 113. Of a total of 353 stomachs, 158 held scales; several were 

 entirely filled with them, and in quite a number upwards of 90 percent of their 

 contents consisted of these insects. * * * The remaining portion of the hemip- 

 terous food of the bush tit, over 31 percent, is made up of plant4ice, tree-hoppers 



