BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Clapper Rail

RallidaeWetland birdsRallus crepitans

Clapper Rail has declined: down 47% on the route-weighted index since 1968.

-47%Since 1968TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
88RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Clapper Rail

The Clapper Rail (Rallus crepitans) is a North American member of the Rails, Gallinules & Coots (Rallidae). In this analysis it is grouped with the wetland birds.

Size
6–19 in long (15–48 cm) — a marsh-dwelling waterbird (typical for the family)
Habitat
Marshes, ponds, lakeshores and other freshwater wetlands.
Diet
Aquatic invertebrates, small fish, frogs and plant matter.
Range
Recorded on 88 Breeding Bird Survey routes across 13 states, most concentrated in the Southeastern Coastal Plain.
Family
Rallidae · Wetland birds

Notable Clapper Rail TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Clapper Rail. See the full index history below.

Clapper Rail Population Forecast

If the recent trend holds, Clapper Rail is projected to stay roughly flat through 2029, near 0.03 (95% range 0.01–0.05). A 5-year backtest shows a typical error of ±27.6%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.03Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.01–0.0595% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±27.6%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Clapper Rail is projected to stay roughly flat through 2029, near 0.03 (95% range 0.01–0.05). A 5-year backtest shows a typical error of ±27.6%, with 100% of held-out values landing inside the 95% band.19662029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.030.010.05
20260.030.010.05
20270.030.010.05
20280.030.010.05
20290.030.010.05

Where the Clapper Rail Is Detected

BBS routes recording Clapper Rail, sized by most recent count.

Clapper Rail Population Trend by State

Clapper Rail population trend by state.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alabama-69%19685
Connecticutinsufficient datan/a1
Delaware+547%19688
Florida-18%196922
Georgia-39%19684
Louisiana+580%197013
Maryland14×19695
New Jersey+186%19813
New Yorkinsufficient datan/a3
North Carolina-47%19707
South Carolina-75%19683
Texas-88%19699
Virginia-61%19735

Clapper Rail Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Clapper Rail population trend by Bird Conservation Region.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Southeastern Coastal Plain-61%196829
New England / Mid-Atlantic Coast+399%196825
Peninsular Florida-30%196912
Gulf Coastal Prairie-68%196921

Clapper Rail Conservation Status

Our route-weighted index shows it down about 47% since 1968.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.