A bal-chatri trap is a good choice to catch owls, according to the University of Nebraska. The trap consists of a heavy weight attached to a small cage that holds a prey item, such as a mouse or rat. Mono-filament lines, tied in small snare loops tied to the outside of the cage, snag the talons and feet of an owl that tries to take the prey. The cage is relatively simple to build and set with items available from a home improvement centre and some basic hand tools.
Cut a rectangular piece of metal screening 12-by-24 inches, leaving wire points along the edge of the screening.
Fold 6 inches of the length of the rectangle up at a 90 degree angle. Curve the centre section so the edges of the bent sections align. Fold the wire points to wrap around the opposite sections to form the floor of a cage.
Cut a circle of metal screening 12 inches in diameter, then cut the circle in half. Align each half circle with one end of the cage. Fold the wire points on the screening around the wire in the half circle to form the ends of the cage.
Cut a 6-inch square from the middle of one end of the cage, trimming the wire points away from the end to form an opening. Cut a 7-inch square of wire screening and trim the wire points off three sides to form a door. Wire the fourth with the wire point remaining to the side to the cage to form a door.
Wire a section of heavy metal pipe with the bailing wire to the bottom of the cage as a weight.
Cut 20 8-inch lengths of 4.54kg. test monofilament fishing line. Tie a small loop knot in the end of each length of line. Insert the other end of each line through the small loop in the end to create a larger snare loop. Tie the free ends of the lines to the outside of the cage covering the cage with loops.
To set the bal-chatri trap, place a mouse or small rat in the trap and wire the door shut. Place the trap in an area frequented by owls. Wait for an owl to strike. Check the trap every hour to prevent a trapped owl from becoming the prey of a larger animal.
Some owl species are protected by law. Trapping owls may be prohibited or restricted in your area or may require a license or permit. Contact your local fish and game department, county extension, or wildlife management office for information on requirements in your area.