16 Jan Purpose: Install on a Bluebird nest box to discourage
House Wrens from using it. Reason: House Wrens are very territorial and will place sticks in ALL nest boxes within their territory, even though they are already using another nest box. They will peck and remove eggs of other species and will even remove the very young nestlings from their box. Since House Wrens are a native species, they are a protected species, so you can only use a device to deter them — you cannot interfere with their nesting
activities. Making a wren guard: Use a material that is similar to what the nest box is made of to construct the guard; ie, wood (pine, cedar, PVC)
Placement/installation: Install the guard on the nest box BEFORE the house wren starts using the nest box. If installed afterwards, it will not be effective. Install it so that it blocks the view of the hole when looking directly at the front of the box and allow a space of at least 2.5 – 3″ between the guard and the nest box entrance hole.
Adaption: Bluebirds and other songbirds should adapt to the wren guard, but always observe to make sure that both parents enter and exit the nest box after it is installed. If not, remove it immediately. Some bluebirders install the wren guard on the box before the bluebirds start the nest building; others install after the first egg is laid. The important thing is to make sure that you verify that the parents accept it.
IMPORTANT —- Remove the guard when the nestlings are between 5-7 days old to make it easier for the parents to feed them and also make it easier for the young to leave the nest when they fledge; bluebirds fledge from day 18-22 days old.
Experts reveal how to keep house sparrow nests out of bluebird houses and away from feeders. Win the bluebird nest vs sparrow nest battle.
Keep House Sparrows Out of Bluebird Houses
“What should I do to keep house sparrows from tormenting wrens and bluebirds? Should I take the birdhouses down?” asks Ruth Armstrong of Niles, Michigan.
Many people love to attract nesting bluebirds. Providing bluebird houses is a very common practice which has significantly helped this species. Nest sites are hard to come by and the boxes that people provide are critical nesting sites.
If you install nest boxes on your property, chances are you’ll attract house sparrows. The male house sparrow has a gray and rusty crown with pale cheeks and a black bib. These non-native cavity nesters wreak havoc on native species. House sparrows were introduced from Europe to New York in 1852 and have thrived in our environment. The species is common throughout most of North America, although its numbers have declined both here and abroad. They are fierce competitors and are more aggressive overall than our bluebirds. This leads to them out competing bluebirds for nesting sites and often killing them.
Keeping house sparrows out of nest boxes is part of being a responsible bird landlord. There are several ways to discourage them from using nest boxes, ranging from boxes specifically designed to dissuade sparrows to traps to eliminate them.
Monitor nest boxes every day. If you see evidence of house sparrows, discard their materials. Bluebirds make nests of fine grasses, woven together in a tidy cup. House sparrow nests are more loosely formed, messy and include scraps of debris. House sparrows are not native or protected by law, so it’s legal to remove their nests to protect native birds. If you don’t have time to tend the box regularly, it’s best to plug the entrance hole until the sparrows lose interest, or take the box down. Better to have no box at all than to allow the sparrows to potentially harm the bluebirds.
We encourage you to visit the North American Bluebird Society’s website for more information, nabluebirdsociety.org.
Keep House Sparrows Away From Bird Feeders
“What seed can I serve to finches and cardinals that sparrows won’t eat? When I fill my feeders, sparrows take over and scare other birds away,” asks Roger Schuette of Staunton, Illinois.
Unfortunately, house sparrows eat practically anything. To discourage these bully birds from gobbling up all the food at your feeders, try eliminating some of their favorites, such as cracked corn and millet. They prefer to feed on the ground or on more open feeders and are somewhat less adept at clinging than other birds. You can discourage them a little and lure finches by putting out Nyjer (thistle) seed in a sock feeder. A tube feeder with very short perches may also be hard for house sparrows to use, while it attracts goldfinches, pine siskins and other small finches. For cardinals, offer sunflower seeds or safflower seeds in a raised feeder, and avoid using inexpensive seed mixes. You’ll probably still have house sparrows, but can possibly keep them from taking over.
Check out the best cardinal bird feeders and birdseed.