Invasive birds of European origin, house sparrows have become pests in many locations, as they compete with several native birds, including blue birds and purple martins. Take advantage of the cavity-nesting instincts of sparrows by making a box trap. By incorporating an “elevator” -- a weight-dependent mechanism -- you can reduce the chances of catching native species in the trap.
Construct the Frame
Cut two 18-inch pieces of cedar board, then cut them in half lengthwise to make two 18-by-5 5/8-inch sections. These pieces form the top and bottom of the trap.
Cut a 10-inch section of the cedar board, then cut it in half lengthwise, yielding two 10-by-5 5/8-inch planks. These two pieces form the left and right sides of the trap. Drill two small pilot holes at each end of the side planks approximately 3/8 inch from the end of the board, and approximately 1 inch from the side.
Cut two 18-inch sections of the cedar board. Cut the boards length-wise to create two 18-by-10-inch pieces for the front and back of the trap.
Lay the bottom panel on your work table. Position the right side panel vertically to form a 90 degree angle with the bottom panel. Drive a screw through each of the pilot holes and into the side of the bottom panel. Repeat the process to attach the left panel, then flip the structure upside down, insert the top between the two sides and drive a screw through each pilot hole to create a square box.
Construct the Elevator
Cut a 12-by-1 1/2-inch cedar board.
Cut off each end of the plastic jug to create a 5 1/2-inch-long plastic tube.
Lay the plastic tube on its side, centered on one end of the 12-inch plank, with the open ends parallel to the long side of the board. Fasten the tube in place with two 1/4-inch screws.
Place the pill bottle, open end up, on the end of the plank opposite the plastic tube. Fasten the bottle to the plank with a screw. The bottle will hold weight to act as a counterbalance to the large tube at the other end.
Mark a line 4-inches from the pill bottle end of the plank. Drill a hole along this line through one side of the plank to the other. Cut two 2-by-2-inch pieces from the cedar board. Attach each piece, set on edge, to the bottom of the trap with screws. Pre-drill the screw holes to prevent the wood from splitting. The 2-by-2s should be placed so that the center of each is 4 inches from the canister end of the plank.
Drill a 1/8 inch hole through each of the 2-by-2s, 1/2 inch from the top. Insert the steel rod through one of the planks, through the balancing board and through the other plank to create a pivot point, like a seesaw. Place just enough weight (coins, washers, nuts) in the pill bottle to raise the plastic jug side of the plank. Add an additional five quarters and two dimes to the canister, which weigh approximately the same as a sparrow.
Finish the Box
Attach the back of the trap to the frame with screws. Attach the front to the frame with hinges.
Attach the latch to the front, opposite the side with the hinges.
Drill a 1 1/2-inch hole in the front of the box, at the center point of the large plastic tube in the raised position. This hole provides the birds access to the trap.
Construct the Down Chute
Drill a 1 1/2-inch hole in the back of the box, at the center point of the large plastic tube in the down position. This hole will allow the bird to exit the plastic tube to the holding cage.
Screw a 4-inch PVC flange over the bottom hole on the back of the trap to create an exit point for the birds. Attach a 4-inch, 90-degree PVC elbow to the flange, with the open side pointing down.
Roll a 4-foot-long, 12-inch-wide section of plastic coated wire mesh into a 4-inch cylinder. Slide the cylinder over the end of the 90-degree-connector. Wrap a cable tie around the mesh and tighten it, so that the mesh cinches tightly around the pipe.
Cut a 4-inch-diameter circle of plastic coated wire mesh to serve as the floor for the holding cage. Attach the bottom to the cylinder with cable ties. Using the tin snips, cut a 4-inch-wide, 4-inch-tall opening near the bottom of the holding cage. Cut off any rough edges from the removed square, and re-attach it to the opening by using two cable ties to create a makeshift hinge on one side of the door.
Attach the paper clip to one end of the rubber band, and attach the other end of the rubber band to the edge of the door. Use the rubber band and paper clip to securely close the door.
Items you will need
- 8-foot-long, 1-inch-thick cedar board, 12 inches wide
- Tape measure
- Circular saw, jig saw or table saw
- Drill and assorted bits
- Deck screws, 1 5/8 inches
- Plastic jug, 1 gallon
- Pill bottle or film canister
- Wood screws, 1/4 inch
- 1/16-inch diameter steel rod, 4 inches long
- Assorted coins
- PVC flange, 4-inch
- 90-degree PVC elbow, 4-inch diameter
- Plastic coated wire mesh
- Cable ties
- Paper clip
- Rubber band
- Be sure to check the trap often so you can remove any captured birds and prevent them from suffering.
- The best way to handle captured sparrows it to donate them to a wildlife center that will use them as food for their captives or to euthanize them as humanely as possible. Laws regarding acceptable euthanasia techniques vary from state to state, so check with your local wildlife department before trapping any sparrows.
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