Trapping Flocks of Chimney Swifts in Illinois

F•GuRg l.Design of the trap used to capture flocks of Chimney Swifts (all measurements are in cm). of the trap.For large chimneys (>41 x 120 cm), the trap was placed over the chimney top without modifications and boards were placed beside the trap to cover any remaining opening (Peters, 1937).The evening before a morning trapping, we counted the number of swifts entering the chimney, and then covered the chimney top completely with screens and boards.The trap was placed over the top of the chimney an hour before dawn.The clear celluloid window was faced east so that the early morning light would cause the swifts to fly out of the chimney towards the window as suggested by Dexter (1950a, b).