This is the Purple Martin Conservation Association 's Repeating Bait Trap. It is a highly-efficient device for capturing English House Sparrows, a major nonnative pest responsible for the decline of the Purple Martin and several other native cavity-nesting birds. When placed and operated properly, this trap can capture up to a dozen of these nest-site competitors per day, alive and unharmed.
This trap comes fully assembled, but you may need to remove any newspaper or "twisty tie" wires stabilizing the pivoting trap chamber. You may also have to unpack, then install, the metal bait tray in its side bait slot, located in the center of the long, narrow side of the trap, about 8" back and 5" up from the bottom corner of the trap that has the wooden bait porch protruding above it.
This trap works by luring hungry House Sparrows up to the wooden perching bait platform on the front of the trap; after that bait is consumed, House Sparrows then walk across the metal pivoting trap chamber to reach the bait in the removable bait tray. When a bird steps onto the mesh of the trap chamber, its weight causes the chamber to pivot down and stay down until the bird "escapes" through the mesh-covered escape hole leading into the holding cage section of the trap. This door opens in only one direction, so trap birds can't escape from the holding cage. After the bird steps off the arm and through the door, the chamber pivots back up, ready to catch the next House Sparrow.
Before placing the trap, the counterweight on the pivoting arm must be adjusted. Loosen the wingnut on the counterweight and slide the large nut toward or away from the pivot point until the arm just balances in the highest "up" position possible. The ceiling of the pivoting trap chamber should be touching the mesh of the trap's ceiling, but be able to Pivot down quickly when a House Sparrow, which weighs about 28 grams, steps onto it. Twenty-eight grams is what 5 U. S. quarters weigh. Try setting 5 quarters on the center of the pivot trap chamber to make sure it falls rapidly. Once the correct counterweight position is determined, tighten the thumbscrew. Note: After a rain, and before the raindrops have dried, the weight of these droplets may cause the pivoting arm to balance in the down position. Eliminate this problem by shaking the water off the trap after each rain.
This trap will work best if you place it on the bare ground, on a sidewalk, driveway, or other area that has no grass. If cover, in the form of bushes, is nearby (within 10-40 feet), all the better. A spot on the ground right beside your regular bird feeders is also ideal, as is a spot directly underneath martin housing, if sparrows have taken up residence there. You can also place the trap in any area where sparrows frequent for dust-bathing, feeding, or roosting. If you need to place the trap in a grassy area, set it on top of a large square of plywood so the seed you spread inside the large holding cage is quite visible. Sparrows like to feed from the bare ground. Regardless of where you place the trap, it should be placed close enough to your residence so that it can be easily checked many times each day.
Proper baiting of the trap with the preferred food of House Sparrows is very important for success. Use red millet, 1/2"-square chunks of white bread, and cracked corn, placed liberally on both the removable metal bait tray, the wooden bait porch just outside the pivot cage, inside the trap, and on the ground just in front of the trap. It is very important to bait all four locations, at least until House Sparrows find the bait station and feed on the bait on the ground outside the trap. Keep the bait fresh, especially after a rain.
Before this trap can lure large numbers of House Sparrows to it, you should make every effort to remove alternate sources of food. In summer when sparrows include lots of insects in their diet, this is impossible, but during the other three seasons, you should eliminate all other bird seed, and spilled grain. Make sure you are not offering millet, cracked corn, or bread anywhere else in your yard. If you are on a farm with lots of spilled grain, chances are less likely that House Sparrows will take notice of the seed and bread in your trap. In such cases, you should also be employing some nestbox traps. Sparrows should first be trained to come to the ground in the vicinity of this trap for food, by liberally sprinkling seed and bread chunks around the front of the trap. Then, gradually, over a several day period, eliminate the grain and bread on the ground, and just keep a few pieces of bait on the trap's perching bait platform. The bait on the removable tray, and inside the trap's holding cage should always be in ample supply. Soon the birds will start coming straight to the trap's bait porch to find food, and once it's consumed, will wander in to get the bait in the removable food tray, and get trapped.
Once you have captured one or more House Sparrows (double check that you haven't captured a nontarget bird species), leave them in the trap's holding cage for as long as you can (several days to a week, or more) by supplying them with a daily supply of water in a dish, bread, and cracked corn. Having birds in the holding cage makes the trap more effective. The hopping, chirping, and fluttering of the trapped birds looking for a way out, attracts other House Sparrows into the trap. One caution: raccoons, feral cats, and rat snakes may also be attracted to the trapped sparrows and try to extract them from the trap at night.
You should visually check your trap every couple of hours. Never leave this trap unattended for more than a few hours. If you have to leave, put the trap away. Since bait traps will lure and trap several species of nontarget seed-eating birds, it is imperative that you learn how to identify these other species and release them quickly when trapped. You must be able to identify what it is you have captured. If you are not absolutely positive of the identification of what you have captured, release it immediately! It is a federal offense to kill any native bird species; the House Sparrow is not a native species, and is not protected. If you cannot distinguish male and female House Sparrows from other common seedeaters, such as House Finches, we suggest you purchase A FIELD GUIDE TO THE BIRDS by Roger Tory Peterson, 1980, Houghton Mifflin Company.
To remove a trapped bird, open the door in the back of the trap and reach in with your arm. Use your other hand to block the entrance. You can grab birds in your bare hands, but sparrows can inflict a painful pinch with their beaks. You may choose to wear a pair of thin work gloves. Remove one bird at a time, then relatch the door each time. If you happen to catch a chipmunk, open the door and let it run out, or put on a thick pair of gloves and remove it by hand.
Once you have removed a captured bird and positively identified it
as a House Sparrow, you have the moral decision of what to do with it.
Some people choose to kill the birds, others transport them 10 to 20
miles away and release them. This latter option, while easier on some
people's conscience, really serves no purpose other than to waste fuel.
All birds have great homing ability and will fly right back in a matter
of hours. If they don't, they will settle into the area where released,
but they will cause others of their kind to disperse outwards. In other
words, it's analogous to trying to bail the water out of a boat by taking
buckets of water from the back and dumping them into the front. Should
you decide to euthanize the birds, we recommend either cervical dislocation
or ether as the means. Cervical dislocation is accomplished by grasping
the bird’s scull in one hand and its body at the base of the skull
in the other hand. Pulling rapidly and firmly in opposite directions
will separate the spinal cord resulting in rapid death. Convulsions
that may follow are due to spinal reflexes, and the birds do not feel
pain. If you choose to use either, which is commonly available as engine
starter fluid, place the bird in a plastic bag and spray ether into
the bag. Don't be afraid to handle the birds.
This bait trap will have the highest capture rate in late sum- mer when naive, fledgling House Sparrows are about, looking for food. It will also have a high capture rate in the fall, winter, and spring, while insects are dormant. It will have a slightly lower capture rate during summer months when House Sparrows have insects available to supplement their diet. You can, however, use this trap all year long.
As stated above, you can maximize the capture rate of this trap by eliminating alternate food sources elsewhere in your yard; luring House Sparrows to feed from the ground in front of this trap, then gradually eliminating the seed there; and by keeping trapped House Sparrows alive in the holding cage section of the trap to act as decoys.
Assembly:
How the Trap Works:
Adjusting the Trap's Counterweight:
Trap Placement:
Baiting the Trap:
Training House Sparrows to Come to Your Trap:
Using trapped House Sparrows as Decoys:
Monitoring the Trap and Identifying Trapped Birds:
Removing Trapped Birds:
What To Do With Trapped House Sparrows:
Best time of Year for Trapping House Sparrows:
Enhancing the Capture Rate of Your Trap:
