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Species · Utah · BBS 2025 Release · 1966–2024

Marsh Wren Population Trend in Utah

All statesForest birds

Marsh Wren in Utah has edged up: up 24% on the route-weighted index since 1993.

+24%Since 1993TrendPercent 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 →
14Routes 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 →
33YearsYears 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 UtahNotable 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 Utah. See the full index history below.

Marsh Wren Population Forecast in Utah

If the recent trend holds, Marsh Wren in Utah is projected to rise about 298% by 2029 — from 0.14 in 2024 to a central estimate of 0.54 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±285.5%, with 100% of held-out values landing inside the 95% band.

+298%Change 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 →
0.54Projected 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 →
0.00–2.295% 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 →
±285.5%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 Utah is projected to rise about 298% by 2029 — from 0.14 in 2024 to a central estimate of 0.54 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±285.5%, with 100% of held-out values landing inside the 95% band.19862029
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 →
20250.610.002.3
20260.590.002.3
20270.570.002.3
20280.560.002.3
20290.540.002.2

Marsh Wren Survey Routes in Utah

Routes recording Marsh Wren in Utah.
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 →
Bear River2120231992
Neponset Res720181995
Callao620241992
Bicknell320131997
Randolph220241993
Promontory120122012
Castle Dale120232016
Salt Springs120051995
Saleratus Cr120072007
Notch Peak119991986
Hardware Ranch120141997
Hatch120112008
Kamas119971997
Boulder120062006

Marsh Wren Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasvermontvirginiawashingtonwisconsinwyoming

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