Measurements
Both Sexes
- Length
- 4.7–5.5 in
12–14 cm - Wingspan
- 11.4 in
29 cm - Weight
- 0.6–0.8 oz
18–22 g
Relative Size
- slightly smaller than sparrows; slightly larger than a House Wren
Other Names
- Troglodyte de Caroline (French)
- Saltapared carolinense (Spanish)
Cool Facts
- The Carolina Wren is sensitive to cold weather, with the northern populations decreasing markedly after severe winters. The gradually increasing winter temperatures over the last century may have been responsible for the northward range expansion seen in the mid-1900s.
- Unlike other wren species in its genus, only the male Carolina Wren sings the loud song. In other species, such as the Stripe-breasted Wren of Central America, both members of a pair sing together. The male and female sing different parts, and usually interweave their songs such that they sound like a single bird singing.
- One captive male Carolina Wren sang nearly 3,000 times in a single day.
- A pair bond may form between a male and a female at any time of the year, and the pair will stay together for life. Members of a pair stay together on their territory year-round, and forage and move around the territory together.
Habitat
Open Woodland
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.
Food
Insects
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.
Nesting
Nesting Facts
- Clutch Size
- 3–7 eggs
- Number of Broods
- 1-3 broods
- Egg Length
- 0.7–0.8 in
1.7–2.1 cm - Egg Width
- 0.6–0.6 in
1.4–1.6 cm - Incubation Period
- 12–16 days
- Nestling Period
- 10–16 days
- Egg Description
- White, cream, or pinkish white, with fine rusty-brown spots.
- Condition at Hatching
- Eyes closed, with pale grayish down.
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.
Nest Placement
Cavity
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.
Behavior
Ground Forager
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.
Conservation
Least Concern
The Carolina Wren thrives over much of the eastern United States. Icy, snowy winters can abruptly reduce local populations, but they soon recover. In fact, the Carolina Wren has been pushing northward with rising average winter temperatures over the past century or so. 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. The Carolina Wren was included on the National Audubon Society’s Blue List in 1980–1981 and Special Concern List in 1982–1986 because populations were considered low in some parts of its range. Overall, though, this species is prospering.
Credits
- Haggerty, T. M., and E. S. Morton. 1995. Carolina Wren (Thryothorus ludovicianus). In The Birds of North America, No. 188 (A. Poole and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.
- Dunne, P. 2006. Pete Dunne’s Essential Field Guide Companion. Houghton Mifflin, New York.