BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Marsh Wren In Gulf Coastal Prairie

All regionsGulf Coastal PrairieForest birds

Marsh Wren in Gulf Coastal Prairie has fallen sharply: down 54% on the route-weighted index since 1980.

-54%Since 1980TrendPercent 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 →
42YearsYears 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 fallen sharply in Gulf Coastal Prairie: down 54% on the route-weighted index since 1980.

Marsh Wren In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Marsh Wren in Gulf Coastal Prairie is projected to stay roughly flat through 2028, near 0.90 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±1332.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.90Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2.995% 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 →
±1332.7%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 Gulf Coastal Prairie is projected to stay roughly flat through 2028, near 0.90 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±1332.7%, with 100% of held-out values landing inside the 95% band.19712028
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 →
20240.940.002.9
20250.930.002.9
20260.920.002.9
20270.910.002.9
20280.900.002.9

Routes In Gulf Coastal Prairie

Routes recording Marsh Wren in Gulf Coastal Prairie.
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 →
Sabine Nwr 2LOUISIANA162017
Sabine NwrLOUISIANA112008
Forked IslandLOUISIANA102019
Ltl Chenier 2LOUISIANA82011
Gran ChenierLOUISIANA61971
Forked Island 2LOUISIANA32011
IndianolaTEXAS21996
DanburyTEXAS21985
CreoleLOUISIANA11971
HackberryLOUISIANA12006
GlencoeLOUISIANA12011
Ltl ChenierLOUISIANA12023
WinnieTEXAS12013
Port AcresTEXAS12022
Bayside 2TEXAS12004

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