TROOP-BIRDS. 



179 



Sub- Family VII. 

 THE TROOP-BIRDS. AGELAIN/E. 



General Characteristics. —Bill the length of the head, or shorter, completely 

 conical, with the sides gradually compressed towards the tip; the culmen straight, 

 flattened, and more or less broad ; the tarsi usually the length of the middle toe • 

 the toes lengthened, slender, the outer united at the base with the middle one, the 

 hind toe long, and all armed with long and rather curved claws. 



These birds are peculiar to the continent of America. The 

 North American species are migratory, and in winter visit the 

 Southern States in large flocks, especially frequenting the vicinity 

 of the sea-coast near large fields of rice and corn. Wilson relates 

 that he has frequently been amused by their aerial evolutions. 

 Sometimes they appeared driving about like an enormous black 

 cloud carried before the wind, and varying its shape every mo- 

 ment : sometimes suddenly rising from the fields around him with 

 a noise like thunder, then descending like a torrent and covering 

 the branches of some detached grove or clump of trees, the whole 

 congregated multitude commenced a chorus which he could plainly 

 distinguish at the distance of more than two miles. They arrive 

 in Pennsylvania in the beginning of March in immense flocks, and 

 commence their attacks on the grubs, caterpillars, and other larvje ; 

 for these they search in the ground at the roots of plants, in or- 

 chards and meadows, as well as among buds, leaves, and blossoms ; 

 and from their known voracity, the multitudes of insects destroyed 

 by them must be immense. During August and September they 

 pour down on the low countries near the coast in prodigious mul- 

 titudes, wheeling and driving over the devoted corn-fields, and 

 filling the air with their numbers. Then commences the work 

 of destruction on the corn till little is left for the industrious 

 husbandman, and on the seeds of the reeds and wild oats, and 

 other plants that abound on the banks of the great rivers. In 

 April they separate in pairs to begin their family preparations. 

 The nest is sometimes placed among the high grass of a watery 

 meadow, or in a tussock of rushes in a marsh, but more frequently 

 about six or eight feet from the ground in a thicket of alders, or 

 in a detached bush. The exterior is formed of rushes and long 

 tough grass twined securely around the neighbouring twigs, to 

 prevent its falling from its flexible support : a similar precaution 

 is used when the nest is made amongst rushes. When placed on 



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