| The difference between what the most and the least learned people know is inexpressibly trivial in relation to that which is unknown." — Albert Einstein |
The above quote is a good description of where bluebirders stand in relation to house sparrow control in spite of decades of trying. And, common house sparrow control recommendations may reduce, rather than increase, available nestboxes for bluebirds:
Remove the Box—Counterproductive, bluebirds need a nestbox, house sparrows do not
Move the box to better habitat—Impractical, habitat is getting worse, not better
For an aerial view of this site, click on: Overview
Western bluebirds on my established trail have been successfully competing with house sparrows since 1999 and I have been trying to identify the "Keys" to success so that Bluebirds on other trails can compete successfully against House Sparrows.
Therefore, the following are discussion points and guidelines until the "Keys" are fine-tuned through additional observation.
Complete Cleanups Require a Full Season
If house sparrows have been allowed to sit on eggs and/or young for any length of time during the previous season, you should expect house sparrow problems at that site for an entire subsequent nesting season—see log notes at: http://home.earthlink.net/~lviolett/conversion.html.
Build to Specifications:
Anyone experimenting with boxes and sharing results has a responsibility to build the test boxes to specifications.
Odd-sized box outcomes might have been the same either way, but it puts a very real question mark into both the experiments and results.
No Bluebird Size Box is Sparrow PROOF
The Mansion is not sparrow proof. If you have house sparrows interested in the mansion without bluebird competition, house sparrows will be able to take the mansion by default. If this happens, monitors have the duty to remove house sparrow nests/eggs on a weekly basis. See log notes at: http://home.earthlink.net/~lviolett/testmirada.html.
Do Not Let House Sparrows Sit in Your Boxes:
Allowing house sparrows to sit on oiled, boiled, or pricked eggs may reinforce their bond commitment to the box and territory. Sneaky techniques to keep house sparrows content/occupied in the box so they don't go on "rampages" may simply prolong the house sparrow problem. In my experience, house sparrows do not go from box to box on retaliatory killing rampages (see above logs).
Communicate
When house sparrows want an occupied nestbox, they go in and break things—this may be a language they understand—start setting up your own communication channels by breaking their eggs and tearing up their nests.
Fact: Honeybees can be trained to arrive at a particular spot exactly at tea time.
One Bluebird-Sized Box Per 2-Acres Forage
Bluebirds need two acres of forage for a nest site. If more than one bluebird-sized box is offered per 2-acre site on my urban trail, the extra box is an open invitation for house sparrows to move in and cause problems. If you have tree swallows to protect both boxes during the bluebird nesting cycle, use your own good judgment. Small holes/boxes for smaller birds (chickadees, etc.) and large holes/boxes for larger birds (hawks, etc.) may, of course, be added.
Close the Deli
Common millet seed will attract common house sparrows. Instead, selectively feed (thistle=goldfinches, nectar=hummers, safflower=house finches). Try to grow native plants to get the ecosystem back in balance for our native species.
Run a mister hose/nozzle into a tree and let it drip into a shallow 1" pottery drip plate to help birds, insects and other wildlife.
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Put your boxes out well in advance of the nesting season to give birds plenty of time to tour the territory and accommodations.
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