Bolt - House Sparrow Trap

INTRODUCTION
Joe Huber is given credit for designing and supplying the first functional in the box sparrow trap that could be made by the average person.  He perfected his now famous trap in the mid 1970’s.  It has been said that it is possible to reduce the sparrow infestation in one's yard by aggressively trapping house sparrows, thereby providing a peaceful environment for bluebirds. This works for me in my yard.

You, too, in time can clear your yard of house sparrows by trapping them one at a time provided you do not offer to the domestic birds feed that attracts house sparrows and you do not permit sparrows to fledge their young.  This does not mean that you will not experience “fly ins” which will attempt to take up housing and establish a new colony.  Statistically, in a utopian situation, a single pair of house sparrows nesting three times a year and fledging four young per nesting could conceivably produce hundreds of offspring in just three years.  Therefore, it is important to capture the male house sparrow as he is the one who usurps the cavity from our cavity nesting birds including the beloved bluebirds.  From this graphic, one can observe it is also important to capture the female.   

I was first exposed to Joe Huber’s trap in 1992.  Although I had been bluebirding for 18 years prior to that time, I was unaware that traps were available.   Since this caught my attention, I obtained plans from Mr. Huber and made one for my own use.  My nest boxes at this time were mounted on power poles.  My first attempt at trapping a sparrow was successful.  However, I was unable to completely control the open end of the plastic bag due to the box being flush mounted on the pole.   This is how I came to realize that a cage on the Huber design trap would be more efficient, plus it would lend itself to the faint of heart since the sparrow could be retained in the cage until one's choice of dispatch could be accomplished.   It also provided immediate identification of the captured bird.

METHODS
Once you own an in-the-box trap using the trigger and gate mechanism of the Huber type trap, I suggest using the following procedures for trapping house sparrows. 

1. The best time for trapping is early or late in the day. 
2. Trapping is most successful during the early part of the nesting cycle, i.e., March through May.  By early June house sparrows have usually found their nesting site, however, this does not mean there would be no attempts to take over a bluebird box during the balance of the bluebird nesting season.
3. Install the trap only after the sparrow nest has been started.  Since the male sparrow guards the box, this reduces the chance of trapping a native bird.  If you wait until the first egg is laid, it enhances the chances of not only catching the male, but also the female. 
4. Lift the steel gate upward from the trap.  Insert trap inside the box aligned with the 1 ½” hole.  (With the Bolt trap you merely insert the hole cage into the 1 ½” hole.)  Reach through the box hole with index finger and hold the wire trigger next to the inside face of the trap. 
5. Set the steel gate on top of the trigger wire.  Close the box door gently and await the sparrow entry.
6. Monitor the trap hourly. This is to make sure a native bird, if captured, can be released unharmed.
7. Once the male is captured reinsert the trap for the purpose of trapping the female.  You are now the guard of the box.  You must observe it frequently to release any native bird that was unfortunate enough to be trapped. 
8. Sometimes the male sparrow becomes leery and will not enter the box.  In this case take a few strands of the nesting material and place it in the 1 ½” opening so as not to interfere with the trigger and gate mechanism.  This makes him think the nest has been invaded.  Therefore, he is more apt to enter the box to investigate. 

RESULTS
Let me give you some examples of how trapping house sparrows help bluebirds to survive.

March 1, 2000 – I removed from one of my nest boxes, a male bluebird that had been mauled to death by a house sparrow’s deadly beak. The next day I placed in the box a Bolt Type “H” trap and caught four male house sparrows over the five days of March 3 through March 7.  On March 20, a pair of bluebirds began building their nest without any further house sparrow intervention.  This pair nested three times that year, laid 15 eggs, and  fledged 11 young bluebirds. 

Early May 2001 - I allowed a house sparrow to build a nest and lay two eggs in a test box which was supplied by John Lapkin, Poland, Ohio.  It had a removable solid wood side and a replacement side that was half plexiglass.  The sparrows built a nest in the box with the wood side installed.  I removed the wood side and replaced it with the plastic side after the nest was completed.  Each day thereafter, I poked a hole in the side of the nesting material checking for eggs.  Only two eggs were laid.  This apparently irritated the male and female house sparrow because they abandoned the box. The male immediately began to take over a bluebird box with four chicks approximately 100 ft. away. I quickly installed another empty nest box 12 feet or so from the bluebird box and waited for the house sparrow to take possession.  Later that day he was spotted going into the box.  The Bolt trap was immediately placed in the box with the expected results.  I am happy to say the four healthy bluebirds fledged on May 18.

You too can achieve successes like this. There are many effective in-the-box sparrow traps available in the marketplace.  Some of the in-box traps I know of are Huber, Huber/Tuttle, VanErt, Gilbertson, Bauldry, etc.  These traps are placed inside the nest box and require a plastic bag placed over the box to retrieve the captured bird. 

As stated above, sparrow traps, including the Bolt trap, can be purchased. The Bolt Type “H” trap is available from Jennabird, P.O. Box 328, Whiteford, MD  21160.  Phone 1-800-500-BIRD as shown on web site www.jennabird.com.

You can also make your own Bolt Trap. Click here for the plans.

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