308 Birds of Colorado 



Whether the birds on the west side of the Divide should be referred 

 to this or some other subspecies cannot at present be definitely decided. 



Habits. — ^The Red-winged Blackbird is an exceedingly 

 gregarious and sociable bird. It is nearly always found 

 in large flocks except during the breeding season, and 

 even then it nearly always breeds in companies. In 

 the early spring the two sexes usually form separate 

 troops. During the greater part of the year its food 

 consists almost entirely of the seeds of various plants 

 and weeds, but in June, while the young are being reared, 

 large quantities of insects, chiefly beetles and grass- 

 hoppers, are eaten. In July and August it resorts to the 

 grain-fields, and when in large numbers does a considerable 

 amount of damage, chiefly to the oat crops. 



It seldom nests far from water — generally among reeds 

 or rushes growing in swamps or sloughs. The nest is 

 a large one, constructed of coarse grasses woveu wet, 

 and lined with finer material of the same sort. It is 

 generally a foot or two above the water. Four is the 

 usual number of eggs ; these are pale greenish, spotted 

 and blotched with various shades of brown and purplish. 

 They average '98 x '69. Only one brood is raised in 

 the season, and the males appear to be polygamous, 

 a small colony often containing only one cock. 



Northern Redwing. Agelaius fhceniceus fortis. 



A.O.U. Checkhst no 498d. 



Description. — Closely resembling A. phoeniceus, but distinctly larger 

 and with a stouter and relatively shorter bill. Length 9-0 ; wing 5-0 ; 

 tail 3-8 ; tarsus 1-19; culmen -SO. 



The female is correspondingly larger than the female of the typical 

 form ; wing 4-15. 



Distribution. — This subspecies, recently discriminated by Ridgway, 

 breeds in the interior districts of British America, on the Mackenzie 

 River and in Athabasca. It migrates south in winter througli the 

 western half of the Mississippi Valley as far south as western Texas 

 and Arizona. The Redwings which winter in Colorado in considerable 



