292 USEFUL BIRDS. 



persistent foe of the Orthoptera. Grasshoppers constitute 

 nearly twenty-two per cent, of its food for the year, and in 

 August and September more than sixty per cent. Alto- 

 gether, seventy-six per cent, of its food for the season con- 

 sists of insects or allied forms, and the other twenty-four 

 per cent, is made up of wild fruit 

 and other vegetable substances, taken 

 mainly in winter. In selecting its 

 food, the Bluebird, like the Robin, is 

 governed as much by abundance as 

 by choice. The vegetable food of the 

 Fig. 128. -The Bluebird's Bluebird proves its harmlessness to 

 crops. It consists almost entirely of 



wild berries ; a few blackberries are eaten, and a little grass 

 and asparagus. Undoubtedly the Bluebird well deserves 

 the welcome annually accorded it. 



WRENS. ,., 



Five species of Wren are found in Massachusetts, but only 

 one, the House Wren, was ever of much economic impor- 

 tance in garden or field. 



The Winter Wren is ordinarily seen in woodlands and 

 thickets. It comes here chiefly in migration, and is not 

 common enough to be of much service to man. 



The Carolina Wren is rare, and the two Marsh Wrens are 

 seldom if ever seen except in wet lowlands. 



House Wren. 



Troglodytes aedon. 



Length. About five inches. 



Adult. Upper parts brown; lower parts grayish-brown, sometimes grayish- 

 white ; wings, tail r and flanks faintly barred with blackish ; tail often held 

 erect. 



Nest. Composed of sticks and rootlets, in a hollow tree or any accessible cavity. 



Eggs. Six to eight ; white, thickly speckled with reddish-brown. 



A once common and familiar species, but now no longer a 

 regular summer resident in the greater part of Massachusetts, 

 the Wren is apparently doomed to give way before the ad- 

 vance of the House (or "English") Sparrow. Attention is 

 called, however, to the desirable qualities of the Wren, in 



