Perch Supply
Nest box specification

Carolina Wren house dimensions

The Carolina Wren nests in domed cup in any cavity — hanging planters, sheds, mailboxes, brush A box built to its measurements — and no bigger — is what makes it choose yours.

Wrens (Troglodytidae)Carolina WrenThryothorus ludovicianus

The specifications

Entrance hole
1 1/8–1 1/2 in
Floor (inside)
4 × 4 in
Mounting height
5–10 ft
Bird size
4.7–5.5 in, 0.6–0.8 oz
Clutch
3–7 eggs
Incubation
12–16 days
Time in nest
10–16 days
Broods
2–3 per season

Build and mounting checklist

  • Drill the entrance to exactly 1 1/8–1 1/2 in — oversized holes let in European Starlings and larger predators.
  • No outside perch: cavity nesters don't need one, and it helps House Sparrows and predators.
  • Unpainted interior, 3/4-inch untreated wood (cedar or pine) or poly-lumber for insulation.
  • Drainage holes in the floor corners and ventilation gaps under the roof.
  • A side or front panel that opens so you can monitor and clean the box.
  • Rough or grooved inner front wall so nestlings can climb out.
  • Pole mount with a stovepipe or cone baffle to stop snakes, raccoons and cats.

When to put up a Carolina Wren box, by state

Boxes should be up and clean a month before local nesting starts. Dates shift with latitude:

PlaceUp byNestingClean out
AlabamaFebruaryMarch–AugustSeptember
FloridaFebruaryMarch–AugustSeptember
GeorgiaFebruaryMarch–AugustSeptember
LouisianaFebruaryMarch–AugustSeptember
MississippiFebruaryMarch–AugustSeptember
South CarolinaFebruaryMarch–AugustSeptember
TexasFebruaryMarch–AugustSeptember
ArkansasMarchApril–AugustSeptember
ConnecticutMarchApril–AugustSeptember
DelawareMarchApril–AugustSeptember
IllinoisMarchApril–AugustSeptember
IndianaMarchApril–AugustSeptember
IowaMarchApril–AugustSeptember
KansasMarchApril–AugustSeptember
KentuckyMarchApril–AugustSeptember
MarylandMarchApril–AugustSeptember
MassachusettsMarchApril–AugustSeptember
MissouriMarchApril–AugustSeptember
NebraskaMarchApril–AugustSeptember
New JerseyMarchApril–AugustSeptember
New YorkMarchApril–AugustSeptember
North CarolinaMarchApril–AugustSeptember
OhioMarchApril–AugustSeptember
OklahomaMarchApril–AugustSeptember
PennsylvaniaMarchApril–AugustSeptember
Rhode IslandMarchApril–AugustSeptember
TennesseeMarchApril–AugustSeptember
VirginiaMarchApril–AugustSeptember
West VirginiaMarchApril–AugustSeptember
OntarioAprilMay–AugustSeptember

Full Carolina Wren species guide →

Frequently asked

What size hole does a Carolina Wren need?

1 1/8–1 1/2 in. A hole cut to this size admits the Carolina Wren (4.7–5.5 in) while keeping out larger competitors.

How big should a Carolina Wren house be inside?

A floor of 4 × 4 in. The Carolina Wren lays 3–7 eggs, so the floor has to hold the full clutch plus growing nestlings.

How high should I mount a Carolina Wren box?

5–10 ft. Mount on a pole with a predator baffle where possible rather than a tree or fence.

How long does a Carolina Wren use the box?

Incubation takes 12–16 days and the young stay in the nest 10–16 days. Broods per year: 2–3 per season.

Sources

  1. Carolina Wren — All About Birds, Cornell Lab of Ornithology
  2. Carolina Wren life history — Cornell Lab of Ornithology
  3. Carolina Wren — Audubon Guide to North American Birds
  4. NestWatch nest box plans and species requirements — Cornell Lab

Timing reflects typical patterns for the region as a whole; local dates vary with elevation and year. Check the linked eBird bar charts for your county.