BirdAnalyst
Species · Idaho · BBS 2026 Release · 1966–2025

Marsh Wren Population Trend in Idaho

All statesForest birds

Marsh Wren in Idaho has edged up: up 10% on the route-weighted index since 1980.

+10%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 →
17Routes 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 →
39YearsYears 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 IdahoNotable 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 Idaho. See the full index history below.

Marsh Wren Population Forecast in Idaho

If the recent trend holds, Marsh Wren in Idaho is projected to fall about 69% by 2030 — from 0.29 in 2025 to a central estimate of 0.09 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±72.8%, with 80% of held-out values landing inside the 95% band.

-69%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 →
0.09Projected 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 →
0.00–0.2795% 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 →
±72.8%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 Idaho is projected to fall about 69% by 2030 — from 0.29 in 2025 to a central estimate of 0.09 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±72.8%, with 80% of held-out values landing inside the 95% band.19732030
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 →
20260.100.000.27
20270.090.000.27
20280.090.000.27
20290.090.000.27
20300.090.000.27

Marsh Wren Survey Routes in Idaho

Routes recording Marsh Wren in Idaho.
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 →
Daniels Res520252025
Springfield320181980
Naples220251973
Cabarton220051999
Blacks Creek220121989
Picabo220251988
Bates220192019
Blackft Res120132009
Preston120231988
Baker120162009
Pasadena Val120141995
Crane Creek120032003
Carey120252025
Iron Springs119891989
Acequia120022002
Henry119831983
Coolin120182018

Marsh Wren Population Trend in Other States

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

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