Nest box specification

Prothonotary Warbler house dimensions

The Prothonotary Warbler nests in tree cavity or nest box standing in or over water A box built to its measurements — and no bigger — is what makes it choose yours.

Wood-warblers (Parulidae)Prothonotary WarblerProtonotaria citrea

The specifications

Entrance hole
1 1/8 in
Floor (inside)
4 × 4 in
Mounting height
3–6 ft over water
Bird size
5.1 in, 0.4–0.6 oz
Clutch
3–7 eggs
Incubation
12–14 days
Time in nest
10 days
Broods
1–2 per season

Build and mounting checklist

  • Drill the entrance to exactly 1 1/8 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 Prothonotary Warbler box, by state

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

PlaceUp byNestingClean out
AlabamaFebruaryMarch–JuneJuly
FloridaFebruaryMarch–JuneJuly
GeorgiaFebruaryMarch–JuneJuly
LouisianaFebruaryMarch–JuneJuly
MississippiFebruaryMarch–JuneJuly
South CarolinaFebruaryMarch–JuneJuly
TexasFebruaryMarch–JuneJuly
ArkansasMarchApril–JuneJuly
DelawareMarchApril–JuneJuly
IllinoisMarchApril–JuneJuly
IndianaMarchApril–JuneJuly
IowaMarchApril–JuneJuly
KansasMarchApril–JuneJuly
KentuckyMarchApril–JuneJuly
MarylandMarchApril–JuneJuly
MissouriMarchApril–JuneJuly
New JerseyMarchApril–JuneJuly
North CarolinaMarchApril–JuneJuly
OhioMarchApril–JuneJuly
OklahomaMarchApril–JuneJuly
TennesseeMarchApril–JuneJuly
VirginiaMarchApril–JuneJuly
West VirginiaMarchApril–JuneJuly
MinnesotaAprilMay–JuneJuly
OntarioAprilMay–JuneJuly
WisconsinAprilMay–JuneJuly

Full Prothonotary Warbler species guide →

Frequently asked

What size hole does a Prothonotary Warbler need?

1 1/8 in. A hole cut to this size admits the Prothonotary Warbler (5.1 in) while keeping out larger competitors.

How big should a Prothonotary Warbler house be inside?

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

How high should I mount a Prothonotary Warbler box?

3–6 ft over water. Mount on a pole with a predator baffle where possible rather than a tree or fence.

How long does a Prothonotary Warbler use the box?

Incubation takes 12–14 days and the young stay in the nest 10 days. Broods per year: 1–2 per season.

Sources

  1. Prothonotary Warbler — All About Birds, Cornell Lab of Ornithology
  2. Prothonotary Warbler life history — Cornell Lab of Ornithology
  3. Prothonotary Warbler — 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.