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Species · Louisiana · BBS 2026 Release · 1966–2025

Marsh Wren Population Trend in Louisiana

All statesForest birds

Marsh Wren in Louisiana has declined: down 42% on the route-weighted index since 1978.

-42%Since 1978TrendPercent 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 →
12Routes In StateSurvey 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 Marsh Wren Trends in LouisianaNotable 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 Marsh Wren in Louisiana. See the full index history below.

Marsh Wren Population Forecast in Louisiana

If the recent trend holds, Marsh Wren in Louisiana is projected to rise about 201% by 2030 — from 0.15 in 2025 to a central estimate of 0.46 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±738.5%, with 100% of held-out values landing inside the 95% band.

+201%Change by 2030TrendPercent 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 →
0.46Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.495% 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 →
±738.5%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 Louisiana is projected to rise about 201% by 2030 — from 0.15 in 2025 to a central estimate of 0.46 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±738.5%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20260.470.001.4
20270.470.001.4
20280.470.001.4
20290.470.001.4
20300.460.001.4

Marsh Wren Survey Routes in Louisiana

Routes recording Marsh Wren in Louisiana.
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 21620172009
Sabine Nwr1120081989
Ltl Chenier 2820112010
Gran Chenier619711971
Ltl Chenier420251986
Forked Island 2320112011
Forked Island220252008
Freetown119781978
Morgan City119751975
Creole119711971
Hackberry120061978
Glencoe120111999

Marsh Wren Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansasmainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.