442 MICHIGAN BIRD LIFE. 
and these distribute their attacks over a much larger area so that the loss 
to any one farmer is very small. 
Studies of the food of the Red-wing bring out three points of particular 
interest: Iteatsimmense quantities of grass seed and weed seeds, a moder- 
ate amount of grain of various kinds, and a con- 
siderable number of insects, the greater part 
being injurious species. According to Beal,* in 
1083 stomachs examined more than half the 
food (55 percent) was grass and weed seeds, 
particularly seeds of pigeon grass or foxtail, 
bitter-weed, smartweed, dock, sorrel, etc.; 14 
percent was grain, half of which was waste 
grain; while the other vegetable matter was of 
little account. Insects formed 26 percent of 
the food, with beetles heading the list and 
caterpillars and grasshoppers next. Practically 
all the insects are taken from the ground and ; Fig. 103. : 
by far the larger part are injurious forms. T#! of Red-winged Blackbird. 
Among these may be named weevils or snout-beetles, cutworms (including 
army worms), span-worms, chafers, and grasshoppers. About one-fourth 
of the beetles are predaceous forms, and thus more or less beneficial, but 
as a whole this blackbird does excellent service for the farmer in ridding 
his fields and meadows of harmful insects. In regions where the bird is 
but moderately plentiful the balance is largely in its favor, but where it 
is very abundant its inroads on grain are too serious to be overlooked. 
TECHNICAL DESCRIPTION. 
Adult male in summer: Glossy velvet black all over, except shoulders (lesser wing- 
coverts) which are bright scarlet, and the middle wing-coverts which are buffy or creamy 
white, forming a broad margin for the red shoulders. In autumn all the black feathers 
(except primaries and tail-feathers) are margined with buff, rusty red, or even chestnut, 
most broadly and heavily on back, scapulars and tertiaries, more narrowly and lightly 
on under parts; bill and feet bluish-black; iris brown. 
Adult female in summer: Smaller and otherwise entirely different. Upper parts 
brownish black, more or less streaked with ashy or whitish, with a more or less distinct 
median light stripe on the crown, and a distinct whitish stripe over the eye; under parts 
streaked lengthwise with whitish and black in almost equal amounts, the chin and throat 
reddish or yellowish and faintly or not at all streaked; shoulders usually mixed red and 
black, occasionally nearly as red as in the male, sometimes without any red; bill brownish 
black; iris brown. Young at first resemble the adult female, but males are soon separable 
by larger size and darker color pattern. 
Male: Length 9 to 10 inches; wing 4.60 to 5.05; tail 3.55 to 3.95; culmen .88 to 1. 
Female: Length 7.50 to 8.50 inches; wing 3.80 to 4.25; tail 3.10 to 3.40; culmen .72 to .80. 
199. Thick-billed Red-wing. Agelaius phceniceus fortis Ridgw. (498d) 
Synonyms: Northern Red-wing. 
Similar to the common Red-wing, but decidedly larger, with the bill 
relatively much shorter and thicker. 
Distribution.—Central North America, breeding northward; migrating 
from Manitoba south to Illinois, Indian Territory, and western Texas, 
westward to and including the Rocky Mountains, and south to Arizona 
and Chihuahua. 
The Thick-billed Red-wing is a new subspecies of blackbird described 
by Ridgway in 1901, and as yet but imperfectly known as to habits and 
*Biological Survey Bull. 13, pp. 33-44. 
