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 Bluvebira’s Bluebird proves its harmlessness to 
oe 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 aédon. 
Length. — About five inches. 
Adult.— Upper parts brown; lower parts grayish-brown, sometimes grayish- 
white; wings, tail, 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 
