BirdAnalyst
Species · BCR 27 · BBS 2025 Release · 1966–2024

Marsh Wren In Southeastern Coastal Plain

All regionsSoutheastern Coastal PlainForest birds

Marsh Wren in Southeastern Coastal Plain has collapsed: down 96% on the route-weighted index since 1968.

-96%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 →
15Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

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

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Marsh Wren has collapsed in Southeastern Coastal Plain: down 96% on the route-weighted index since 1968.

Marsh Wren In Southeastern Coastal Plain Population Forecast

If the recent trend holds, Marsh Wren in Southeastern Coastal Plain is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±801.7%, 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 →
0.00Projected 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 →
0.00–0.0895% 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 →
±801.7%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, Marsh Wren in Southeastern Coastal Plain is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±801.7%, 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 →
20250.000.000.08
20260.000.000.08
20270.000.000.08
20280.000.000.08
20290.000.000.08

Routes In Southeastern Coastal Plain

Routes recording Marsh Wren in Southeastern Coastal Plain.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Dauphin IsALABAMA31989
PungoVIRGINIA31979
Alabama PtALABAMA21973
KellerGEORGIA21982
Johns IsleSOUTH-CAROLINA21976
Kiawah IslandSOUTH-CAROLINA22024
Dauphin Is 2ALABAMA12003
SteinhatcheeFLORIDA11995
St Vincent IFLORIDA12007
Harrietts BlGEORGIA12006
DarienGEORGIA12017
Colonels IslandGEORGIA12017
MerrimonNORTH-CAROLINA11985
Myrtle GroveNORTH-CAROLINA12019
JamestownSOUTH-CAROLINA11970

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.