Home
Search the site
Tennessee Wildlife
  Viewing Trail

FAQ
Critter of the Month
Seasonal Events
Monthly Gallery
Backyard Wildlife Info
TWRA Publications
Woodworking for Wildlife
Education Tools
Links to Related Sites
Sponsors
About us
Contact Us

Join our Mailing List










Policies & Privacy
©Copyright 2017 TWRA






Woodworking for Wildlife

House Wren
Download this page and nest box design (PDF)

The House Wren is a common backyard bird in most of the U.S. and parts of Tennessee. Like other wrens, it is attracted to human development, with the numerous nooks and crannies provided by barns, garages and other structures. Though very small birds, the House Wren is a fierce competitor for nest cavities, sometimes dragging eggs and young of other species out of a nest, and even killing adults. In some areas, it is a main source of nest failure for Bluebirds. However, it is a native bird that is protected by law.

Jump to House Wren nest box design

Description/Identification see PHOTOS
A small and compact wren with a flat head and long, curved beak. It has short wings and a relatively long tail that it often keeps cocked above the body. Both sexes are dull brown overall with darker brown barring on wings and tail. Very pale eyebrow compared to other wrens.

Habitat
The House Wren is found in open woodlands, forest edges, and urban and suburban parks, backyards and farmyards. It is particularly attracted to areas with scattered trees, shrubs and brushy tangles.

Diet
This species forages through thickets and shrubs for insects and spiders. Also eats flying insects, such as leafhoppers and flies.

Breeding and Nesting
In early spring the male House Wren starts building nests to persuade a female to mate with him. He piles twigs into an old woodpecker hole, natural crevice or other cavity to serve as a base for a soft-lined cup made of a few feathers and grasses. The twigs are often mounded up into a barrier between the nest and cavity hole, providing protection from weather and/or predators.
Clutch size: 5-9 white to pink white or grayish eggs with reddish blotches
Incubation period: 9-16 days. The nestlings are fed by both parents and fledge in 15-17 days.

May have more than one brood per season.

Song: The song is an exuberant jumble of bubbling trills and rattles. They sing from early spring into mid-summer.

Listen to song HERE

Fascinating Facts

  • As with other bird species, blood-sucking nest parasites can infest a nest and be a problem for the developing nestlings. Some House Wrens have been found to put the egg cases of predatory spiders into the nest material. In a recent laboratory study, when the spiders hatched they fed on the nest parasites and likely improved the health of the nestlings.

Nest Box for House Wrens

Preferred box design for House Wrens is slightly smaller than the NABS Eastern Bluebird box with a 1 ¼ inch entrance hole. This box design may also be used by Carolina Chickadees, White-breasted Nuthatches, Tufted Titmice, and Prothonotary Warblers.

House Wren Box Design PDF


Nest Box
• Use natural, uncoated wood such as cedar or redwood which are more durable than pine or exterior plywood. Use at least ¾ inch boards.
• Make corner opening on the floor bottom of the box to allow drainage and facilitate ventilation
• Never include an under-the-hole perch.
• The roof should provide sufficient overhang beyond the box entrance or vent holes to protect the birds from the elements.
• The roof should have a minimum of ½ inch overhang at the back.
• The nest box must have watertight construction at all seams.
• Cross ventilation is strongly recommended.
• Include one hinged, side panel that opens for easy monitoring and cleaning.

Box Placement
To attract House Wrens, place your box in a more wooded area than recommended for Eastern Bluebirds. Place the box near woods, shrubs, and thickets, which are used for foraging and hiding from predators. Farms or barnyards where animals are fed are not recommended sites for boxes because these are attractive to House Sparrows. Avoid placing your box where pesticides or herbicides are used.

The nest box should be mounted on a ½" to ¾" electrical conduit post placed over a 3 to 4 ft. piece of rebar. Both materials are available at hardware stores. Pound the rebar into the ground and slide the post over it, making sure that it is solid and steady. Mounting the box on a tree or fence post is not recommended.

Mount the box so that the entrance hole is about 5 ft. from the ground and facing, if possible, to the east, away from direct summer afternoon sun and from north winds that may drive rain into the box. A tree or shrub that is within 100 feet of the box will provide a perch for the adults and a safe spot to land for the fledglings' first flight. If you plan to put up multiple boxes in an area, we recommend placing boxes at least 100 yards apart to reduce competition between House Wrens and other species.

Install a baffle to keep snakes, raccoons and other predators out of the nest.

Squirrels or woodpeckers sometimes damage the entrance hole, making it larger and allowing undesirable species to enter the box. This can be resolved by placing a copper or other metal hole-guard (available at hardware or wild bird retailers) over the damaged hole. A block of 1.5" hardwood with an entrance hole made and placed over the original hole will also work.

Monitoring Your Box
To prevent doing more harm than good, do not install a box if you do not plan to monitor it. Check the box once a week during the nesting season to monitor status of House Wrens or other native nesting species, check for leaks and damage on the box, and provide you with a wonderful education. Keep in mind that even the perfectly built and placed box may not attract a breeding pair the first year. If after two years of not having native birds nesting in your box, you may want to move it to another site.

Monitoring tips:
-Research to recognize the eggs and nests of other species, especially House Sparrows
-Check the box only on a warm, dry day.
-On your day to check the box, try to observe activity of the adults and approach the box while they are away.
If they are present, don't worry that they will desert the nest. They may fly to a perch to watch you, and you may receive a few scoldings from them, but they will return when you leave the area.
-Approach the box quietly.
-Check for ants or other parasites.
-Remove and destroy House Sparrow eggs and nests.
-To prevent premature fledging, do not open the box after 12 days from the time the nestlings hatch.
-Remove and dispose of the nest in the trash soon after the nestlings have fledged. They will not return to the nest and the adults will build another, cleaner nest for the next brood.
-Keep records of the activity in your box.