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Species · Minnesota · BBS 2026 Release · 1966–2025

Marsh Wren Population Trend in Minnesota

All statesForest birds

Marsh Wren in Minnesota has surged: up 230% on the route-weighted index since 1969.

+230%Since 1969TrendPercent 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 →
66Routes 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 →
58YearsYears 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 MinnesotaNotable 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 increasecomputed 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 surged in Minnesota: up 230% on the route-weighted index since 1969.

Marsh Wren Population Forecast in Minnesota

If the recent trend holds, Marsh Wren in Minnesota is projected to fall about 12% by 2030 — from 2.4 in 2025 to a central estimate of 2.1 (95% range 1.2–3.1). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.

-12%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 →
2.1Projected 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 →
1.2–3.195% 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 →
±15.5%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 Minnesota is projected to fall about 12% by 2030 — from 2.4 in 2025 to a central estimate of 2.1 (95% range 1.2–3.1). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20262.01.13.0
20272.11.13.0
20282.11.13.0
20292.11.13.0
20302.11.23.1

Marsh Wren Survey Routes in Minnesota

Routes recording Marsh Wren in Minnesota.
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 →
Tracy4420252005
Sherburne Nr2120251990
Big Stone2020121995
Chokio1420251969
Little Fork1219901990
Fairmont1220252003
Cohasset1119901990
Glyndon1020251980
Ashby920211997
Maynard720151986
Chandler520252022
Knapp520251967
Appleton520251980
Lake Bronson520111998
New London520241994
Minnetonka420221969
Beltrami320061976
Brook Park320252024
Glenwood320181993
Lakeville219991976
Courtland220251978
Evergreen220181967
Caledonia 2220242016
Debs220231984
Wylie220081970

Marsh Wren Population Trend in Other States

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

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