34 FOOD OF BOBOLINK, BLACKBIRDS, AND GRACKLES. 
species. In many places, especially on the borders of shallow lakes, 
thousands of acres of rushes and reeds of various kinds afford nesting 
sites for redwings, yellowheads, and marsh wrens, while myriads of 
more aquatic species swim in the waters below and nest amid the 
broken herbage. It is from such breeding grounds that the vast 
flocks are recruited that make such havoc upon fields of grain and call 
forth the maledictions of the unfortunate farmer. East of the Appa- 
lachian Range the conditions are different. Marshes on the shores of 
lakes, rivers, and estuaries are here the only sites available for breed- 
ing purposes, and as these are more restricted in number and area 
than the western breeding grounds the species is much less abundant 
than in the West. 
Fic. 4.—Red-winged blackbird. 
Like their associates, the marsh wrens, and their neighbors, the 
hank swallows, the redwings are eminently gregarious, living in flocks 
for the greater part of the time and breeding in communities which 
vary in size according to the area of the swamp they occupy. Some- 
times these. colonies are reduced to a single family, which in such 
cases usually consists of one male bird with several females and their 
nests; for this species practices polygamy, a habit noted in the case 
of only a few species of song birds. 
During the winter the redwings are in the South, but may occasion- 
ally be found as far north as latitude 40°, and stragglers may occur at 
any point within their summer range. (A young male was shot by the 
writer in central Iowa in January. 1874. and one bird whose stomach 
