BRONZED GRACKLE 417 



mained intact, and did not stop to rest. The flight was near the ground, and fol- 

 lowed the contour of the country closely, rising only to clear farm buildings and 

 woods, then dipping again to the former level. The lowermost birds were scarcely 

 more than twenty feet from the ground. While the birds were flying there was 

 no singing and not much noise of any kind except that made by the wings. It was 

 evident that the birds had some definite feeding ground selected, toward which 

 they were hurrying in a straight line. 



In the evening the first birds arrived at the roost at 5:14 p.m. Be- 

 tween 5:34 and 5:45 about 5,000 arrived, coming in companies of from 

 200 to 800, an almost continuous flight. The birds continued to come 

 in until a few minutes after 6. By 6:15 practically all were out of 

 sight in the foliage and a few minutes later all noise had stopped. 



A study of the flocks at a point away from the roost revealed that 

 the mass assumed definite patterns of narrowed and expanded parts. 

 It became more drawn out and broken as it proceeded. The vanguard 

 would stop at some treetop and rest until the others had passed over, 

 at which time it arose and formed the rear guard. In this way the 

 whole flock secured a short breathing time, part by part. Rarely, two 

 flocks were formed during the flight. 



"There was no diminution in the number occupying the roost up to 

 September 21, but not one bird appeared at the old stand on the two 

 succeeding days. On the 24th less than a hundred occupied the trees 

 during the night and none visited it afterwards." 



Charles R. Keyes (1888) describes the great blackbird flights at 

 Burlington, Iowa, as follows: 



During September and October the cornfields of Iowa are visited by countless 

 numbers of these black marauders, which wander about in mixed flocks of several 

 thousands, passing the day in the fields and the night in woodland or marshes. 

 And it is during this period that so many thousands are poisoned and killed by the 

 farmers. About the first of October the birds begin * * * to rise out of the 

 swamps and radiate in all directions towards the inland cornfields, where they 

 spend the day, returning again to the swamps before sunset. These flocks are 

 often a quarter of a mile in width and are more than an hour in passing — a great 

 black band slowly writhing like some mighty serpent across the heavens in either 

 direction, its extremities lost to view in the dim and distant horizon. Not un- 

 frequently, three or four such vast flocks are in sight at one time. How far away 

 from their night resorts they go each day has not been observed; an hour and a 

 half before sunset, twelve miles away from the river, the mighty armies of Black- 

 birds are still seen coming over the distant hills and directing their course toward 

 the marshes. It is evident, however, that many miles are daily traversed in their 

 journeys to and from the feeding grounds. Making liberal deductions for any 

 possibility of over estimating, the numerical minimum of individuals in a single 

 flock cannot be far from twenty millions. 



It has been noted by many observers that the times when blackbirds 

 arrive and leave the roost varies according to the length of day. Mar- 

 garet M. Nice (1935) made observations of the bronzed grackles and 

 starlings which roosted in the shade trees of a residential district of 



