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.

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.