Carolina Wren Life History

Habitat

Carolina Wrens frequent vegetated habitats such as brushy thickets, lowland cypress swamps, bottomland woods, and ravines choked with hemlock and rhododendron. They gravitate toward shrubby, wooded residential areas, overgrown farmland, dilapidated buildings, and brushy suburban yards. Back to top

Food

Insects and spiders make up the bulk of this wren’s diet. Common foods include caterpillars, moths, stick bugs, leafhoppers, beetles, grasshoppers, crickets, and cockroaches. Carolina Wrens occasionally eat lizards, frogs, or snakes. They also consume a small amount of plant matter, such as fruit pulp and seeds from bayberry, sweetgum, or poison ivy.Back to top

Nesting

Nest Placement

Carolina Wrens nest in open cavities 3–6 feet off the ground, in trees, overhangs and stumps. The first nest is sometimes built on vegetation-shaded ground. Near homes, they're versatile nesters, making use of discarded flowerpots, mailboxes, propane-tank covers, and a variety of other items. Their nests have even been found in old coat pockets and boots. Males often build multiple nests before the pair makes a final selection.

Nest Description

Male and female Carolina Wrens build their nests together. One member of the pair may stay at the site while the other gathers material. The first nest can take a week or more to build, but later ones take shape in as few as 4 days. The bulky nest is cup-shaped, usually domed, with a side entrance and often a woven extension like a porch or entrance ramp. It's loosely constructed of a great variety of materials such as bark strips, dried grasses, dead leaves, pine needles, hair, feathers, straw, shed snakeskin, paper, plastic, or string). The female lines the nest's inner bowl and may add nest material after incubation has begun. Nests may range from 3 to 9 inches long and 3 to 6 inches wide.

Nesting Facts

Behavior

Carolina Wrens usually go about their business alone or in pairs; after nestlings have fledged, you may see family groups feeding together. Feeding on or near the ground, the wrens run, hop, and flit around leaf litter and tangled vegetation; they dodge in and out of dark spaces created by downed trees, decaying logs, old stumps, and upturned roots. They climb up vines, trunks, and branches, poking into squirrel nests and probing nooks and crannies in search of insects. Carolina Wrens use their curved bills to turn over decaying vegetation and to hammer and shake apart large bugs. They roost in bird boxes, abandoned hornet nests, hanging plants, garages, barns, old nests, and other shelters. A weak flyer, this wren makes brief, quick aerial forays over short distances. Pairs stay bonded year-round, with no vacation from singing or defending territory. Back to top

Conservation

Carolina Wrens are common across their range and their populations increased between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 19 million and rates them 7 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. These birds thrive over much of the eastern United States. Icy, snowy winters can abruptly reduce local populations, but they soon recover. In fact, with rising average winter temperatures over the past century or so, the Carolina Wren has been pushing northward. The species has probably benefited from forest fragmentation in some areas and from reforestation in others—both processes create the tangled, shrubby habitat these birds use. In recent decades, the Carolina Wren has also profited from a proliferation of backyard bird feeders. This is especially true in northern portions of the bird's range, where natural food sources can disappear beneath winter snow and ice.

Credits

Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.

Haggerty, Thomas M. and Eugene S. Morton. (2014). Carolina Wren (Thryothorus ludovicianus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

Back to top