180 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



food, as well as digested food, and removed all waste matter from 

 the nursery. At first tender insects were doled out to them. 



"On the third morning I peeped through a crevice in the blind 

 eight hours, during which period the female fed the young digested 

 food 17 times, and both birds made 33 visits with fresh insect food. 

 Spruce bud moths were fed on 15 occasions. From 2 to 12 moths 

 were given at a repast, but mostly they were given by the beakful. 

 Caterpillars were dealt out 13 times. The quantity varied from one 

 to a billful, and the mouth of the olive-backed thrush is capacious. 

 Usually the birds brought a goodly number. All four birds were fed 

 on all these visits." 



Her list of food given to the young includes "all colored inchworms, 

 cutworms, earthworms, yellow-green, blue-green, and gray-green cat- 

 erpillars, all tones of tan and brown caterpillars, rosy maple-moth 

 caterpillars, rosy maple moths, June bugs, click beetles, flying ants, 

 craneflies, geometrid and spruce bud moths, orange- colored worms, 

 grasshoppers, larvae of cherry hawkmoth, and fruit." 



The young thrushes increase in size and weight very rapidly. Miss 

 Stanwood measured and weighed the young in four nests every day 

 during their nest lives. One of these, during 1 1 days, grew in length 

 from 1% to 4% inches; and the same bird increased in weight from 

 60 grains to 445% grains. For further details, the reader is referred 

 to her published paper (1913). The feather tracts were in evidence 

 by the end of the first day; on the second day the eyes were beginning 

 to open; all the feather tracts were well indicated on the third day; 

 by the end of the fifth day the bird was well covered with quills and 

 pinfeathers; feathers began to appear on the seventh day; and by the 

 end of the tenth day the young bird was well feathered and practically 

 free of quill casings. With the gain in size and weight came an in- 

 crease in activity and the development of the sense of fear. 



Both parents assisted in cleaning the nest. At first the excretal 

 sacks were eaten; the birds began carrying away some of the sacks 

 on the ninth day, but some of the excreta were eaten up to the end of 

 the nest life of the young. In a later note she says that the female 

 begins to incubate sometimes after the second egg is laid, but always 

 after the third egg is deposited. 



Plumages. — The natal down in the young olive-backed thrush is 

 very dark brown, Miss Stanwood says "so dark brown that it looked 

 black." 



The young thrush, in fresh juvenal plumage, is described by Dr. 

 Jonathan Dwight, Jr. (1900), as follows: "Above, olive-brown, wings 

 and tail darker, the feathers of the pileum, back, lesser, median and 

 sometimes part of greater coverts and the rump with linear shaft 

 streaks or terminal spots of buff. Below, strongly washed with buff 



