Bird Profile

House Wren

The House Wren is a pure insect eater, so no feeder you own will attract one. A nest box, a messy hedge and no pesticides will. Its habits toward neighbors are another matter.

The House Wren (Troglodytes aedon) is a small, plain, grayish-brown wren about 4.5 inches (11 cm) long with a faint pale eyebrow, a thin curved bill, a barred tail it holds cocked, and a bubbling song out of all proportion to its size. It eats insects and spiders, and it will not use your seed feeder.

That is the single most useful thing to know about it. Every guide to attracting House Wrens comes down to two things: a cavity to nest in and a yard with enough invertebrates to feed a brood. Seed, suet blocks and nyjer are irrelevant.

This profile covers how to separate it from the other small brown wrens, when it shows up and leaves, why males build nests they never use, the nest box dimensions and spacing that work, and its reputation among people who also keep bluebird boxes, which is deserved.

How to identify a House Wren#

Think small, brown and busy. The upperparts are dull grayish brown with fine dark barring on the wings and tail, the underparts are pale gray-buff, and the whole bird is about the size of a chickadee but longer-billed and rounder-bodied.

The eyebrow is the key mark, mostly by its absence: a House Wren shows a faint, blurry pale line over the eye, not the crisp white stripe of its larger relative. Sexes look alike.

Behavior gives it away first. House Wrens move in low, quick bursts through shrubs, brush and woodpiles, tail cocked, scolding at anything that comes near. They spend more time in dense vegetation than in the open, and they are far more often heard than seen.

House Wren or Carolina Wren#

In the eastern US these two overlap all summer, and they are easy to separate once you look at three things.

Winter settles it in the North: House Wrens are gone. In the Southwest and West, Bewick's Wren is the likelier confusion, and it is longer-tailed with white tail corners and a bright white eyebrow. Winter Wren and Pacific Wren are much smaller, darker and stub-tailed, and they skulk on the forest floor rather than in yard shrubs.

Where and when you will see one#

House Wrens breed across nearly the whole lower 48 and up into southern Canada, in yards, orchards, farm edges, parks and open woodland. They want edge habitat: scattered trees with shrubby understory, not deep forest and not bare lawn.

Arrival is late April to mid-May in most of the North, and males begin singing immediately and continuously. Departure runs from late August into October, and birds winter in the southern tier of states and Mexico. In the Deep South and the Southwest they are the wren of winter, not summer.

Once a male is on territory he sings from dawn until well into the afternoon, and a single unmated male can sing several hundred times an hour. If a small brown bird has been shouting in your hedge since dawn every day in May, this is it.

What House Wrens eat#

The diet is close to entirely invertebrate: caterpillars, beetles and their larvae, grasshoppers, crickets, spiders, flies, moths, earwigs and snails. Nestlings are fed the same, delivered every few minutes for two weeks straight, which is why insect abundance decides whether a pair succeeds.

The practical consequence is that a heavily sprayed lawn with clipped ornamental shrubs cannot support a brood no matter how good the box is.

A shallow bird bath with a pebble or two for footing is more likely to draw a House Wren into view than anything you can fill a feeder with.

Nest boxes and dummy nests#

House Wrens are cavity nesters and are not fussy: old woodpecker holes, natural cavities, boxes, and the usual assortment of flowerpots, mailboxes and hanging equipment.

A workable box is small and simple.

The smaller hole matters: 1.25 inches (3.2 cm) or less excludes starlings entirely and makes the box less attractive to House Sparrows.

Then comes the behavior that generates the most questions. The male arrives first and stuffs twigs into every suitable cavity in his territory, filling two, three or more. The female inspects them, picks one, and lines the chosen cup with grass, rootlets, feathers and hair. The rest sit half full of sticks all summer. These dummy nests appear to serve courtship and territory defense at once, and they are entirely normal.

Clutches run 5 to 8 eggs, incubation is about 12 to 14 days, young fledge at roughly 15 to 17 days, and most pairs raise two broods. Cleaning out old sticks between seasons is fine and worth doing.

The aggression, stated plainly#

House Wrens compete for cavities by attacking their neighbors. Documented behavior includes puncturing and removing the eggs of other cavity nesters, killing nestlings, evicting adults, and filling nearby boxes with sticks to render them useless. Chickadees, titmice, Eastern Bluebirds, tree swallows, prothonotary warblers and other wrens are all affected.

This is native behavior in a native bird, and it is not comparable to the introduced House Sparrow problem, where control is legal and often recommended. House Wren nests are protected, and removing or destroying them is not an option.

What you can do is site boxes to reduce the collisions. House Wrens defend territories of roughly an acre and prefer boxes near cover. Bluebirds and swallows prefer boxes in the open. Putting bluebird boxes at least 100 feet (30 m) out from the shrub line, and any wren box on the far side of the yard, cuts conflict substantially. The siting logic for each species is covered in nest boxes: sizing and siting and how to attract bluebirds.

Population and conservation#

House Wrens are common and widespread, and their overall population has been stable or slightly increasing over recent decades. They adapt well to suburban yards, farm edges and parks, which is unusual among insect-eating songbirds and largely explains the stability.

The pressures that do matter are the general ones: insecticide use that thins the invertebrate supply, removal of dead wood and shrubby edge, and free-roaming cats. None of these are specific to wrens, and all of them are addressed in the bird-friendly yard checklist.

What to do this spring#

• Put up one small box with a 1.25 inch (3.2 cm) hole by early April, near shrubs, 5 to 10 feet (1.5 to 3 m) up.
• Leave a brush pile and some leaf litter for the insects the wrens actually eat.
• Stop spraying the lawn and the shrubs.
• Keep bluebird and swallow boxes well out in the open and far from the wren box.
• Do not clear out a stick-filled box in midsummer; it may be a dummy nest in an active territory.
• Expect no feeder visits, and read how to attract wrens for what does work.