House Wren

House Wrens (Troglodytes aedon) are familiar birds, largely because they thrive in altered habitats, including forest clear-cuts, parks, brushy thickets, and residential areas, and because of their habit of nesting in man-made objects, such as bird houses, mail boxes, old hats, and other objects left outside. Like other wrens, House Wrens have loud bubbling songs and harsh scolding call notes.

by John Rakestraw
Photograph (C) 2009 Rick Brumble

Of the four species of wrens that live in the Portland/Vancouver area, House Wrens are the most plainly marked. The best field mark for recognizing a House Wren is actually the lack of field marks. This species is dull brown above and dull gray below, with a little dark barring on the wings and tail. There may be an indistinct pale line above the eye, but nothing like the bold white eyebrow seen on Bewick’s Wren. Winter Wrens are similar to House Wrens, but Winter Wrens are much darker below with barring on the sides, a more prominent pale eyebrow, and a shorter tail. Marsh Wrens are more rusty brown, with a bold white eyebrow and white streaks on the back. Marsh Wrens are often found in cattails, where you would never expect to see a House Wren.

While the other wren species are found here year-round, House Wrens spend the winter in the southern U.S. and Mexico. They arrive in the area in April, and most have left by mid-September. Males begin building nests by placing small sticks in a cavity, building a platform with a depression in the middle. The female completes the nest by lining the depression with soft grasses and hair. Clutches consist of 3-8 eggs.

House Wrens aggressively defend their nesting territory. Males will sometimes fill nearby nest boxes with sticks, just to keep other birds from using them. House Wrens are also known to usurp the nests of other birds and destroy their eggs.

House Wrens feed exclusively on insects, so they are not likely to come to a bird feeder. But they do readily accept bird houses during the nesting season. They will use almost any kind of house, but if you want to offer a house just for wrens, choose a box with a 1” opening. This size of hole is too small for other species. Place the nest box in an area with brush piles or other heavy cover nearby.