442 



Michigan bird life. 



and these distribute their atta(^ks over a imicli hirger area so that the loss 

 to any one farmer is very smalL 



Studies of the food of the Red-wing bi-ino; out three points of })articulai' 

 interest: It eats immense 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 

 108-3 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 

 l)y far the larger part are injurious forms. 

 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 l)e overlooked. 



Fig. 103. 

 Tail of Red-winged Blackbird. 



TECHNICAL DESCRIPTION. 



Adult male in summer: Glossy velvet black all over, except shoulders (les.ser 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. ITpper j^arts 

 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 tlie eye; under parts 

 streaked longtiiwise with whitish and black in almost equal amounts, tlie chin and throat 

 reddish or yeUowish 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 

 l)lack; iris brown. Young at first resemble the adult female, but males are soon separable 

 l)y 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 phoeniceus fortis Ricl(/ir. (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 Ridgwa}^ in 1901, and as yet but imperfectly known as to habits and 



♦Biological Survey Bull. 13, pp. 33-44. 



