252 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



But by far the worst enemy of the crow is man. Where crows are 

 numerous, especially in their winter roosts, enormous numbers are 

 killed by bombing with dynamite. As one example of this, Dr. Walter 

 P. Taylor (MS.) tells us that in Collingsworth County, Tex., on 

 April 7, 1937, bombs were exposed in a shinnery clump to kill crows. 

 There was one stick of dynamite to each bomb, and the bombs were 

 connected with wires, so that they could be fired simultaneously. Sixty 

 bombs were set off at the first discharge, at which it was estimated 

 that 40,000 crows were killed; at the second shot, 120 bombs were set 

 off, killing nearly as many more. Other bombing operations are men- 

 tioned under "Roosts." 



Roosts. — During the summer crows associate only in pairs at their 

 isolated breeding places, but in fall they exhibit a marked gregarious 

 inclination, and birds from many miles of territory congregate in im- 

 mense roosts comprising thousands, sometimes tens and even hundreds 

 of thousands, of individuals. These roosts are not only made up of 

 the birds breeding in the region but the flocks are augmented by birds 

 that have migrated from nesting grounds located farther to the north. 

 In New England there is a marked tendency for the crows to move 

 from inland areas to roosts established near the coast. Food is the 

 primary factor involved in this shift; whereas the feeding grounds in 

 the interior become covered with snow and ice, the seacoast provides 

 an uninterrupted food supply that is replenished with every flow of 

 the tide. Even the severe winter weather does not drive the hardy 

 members from the roosts established in the dense coniferous forests 

 that fringe the coast. Most of the roosts in northern New England are 

 comparatively small, however, and one must go farther to the south- 

 ward before meeting with aggregations of unusual size. 



Townsend (1918) has presented a vivid account of a crow roost that 

 contained approximately 12,000 individuals, located in the thickets and 

 hardwoods on Castle Hill near Ipswich beach, Mass. Following are 

 extracts from Dr. Townsend's paper, which portray in detail scenes 

 similar to those many others have experienced. 



In the short winter afternoons the Crows begin their flight to the roost long 

 before sunset. By three o'clock or even as early as one o'clock, especially in j 

 dark weather and in the short December days, this bed-time journey begins, j 

 while in the latter part of February the flight is postponed until half past four ■ 

 or a quarter of five. From every direction but the seaward side the Crows direct 

 their course towards the roost Three main streams of flight can be distinguished: 

 one from the north, from the region of the Ipswich and Rowley "hundreds," — 

 the great stretches of salt marshes that extend to the Merrimac River, — a second 

 from the west and a third, — apparently the largest of all, broad and deep and 

 highly concentrated, — from the south. 



