BirdAnalyst
Species · Wyoming · BBS 2025 Release · 1966–2024

Marsh Wren Population Trend in Wyoming

All statesForest birds

Marsh Wren in Wyoming has fallen sharply: down 57% on the route-weighted index since 1979.

-57%Since 1979TrendPercent 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 →
25Routes 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 →
40YearsYears 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 WyomingNotable 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 Wyoming: down 56% on the route-weighted index since 1979.

Marsh Wren Population Forecast in Wyoming

If the recent trend holds, Marsh Wren in Wyoming is projected to stay roughly flat through 2029, near 0.22 (95% range 0.00–0.84). A 5-year backtest shows a typical error of ±144.6%, with 100% of held-out values landing inside the 95% band.

-5%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 →
0.22Projected 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 →
0.00–0.8495% 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 →
±144.6%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 Wyoming is projected to stay roughly flat through 2029, near 0.22 (95% range 0.00–0.84). A 5-year backtest shows a typical error of ±144.6%, with 100% of held-out values landing inside the 95% band.19772029
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 →
20250.220.000.84
20260.220.000.84
20270.220.000.84
20280.220.000.84
20290.220.000.84

Marsh Wren Survey Routes in Wyoming

Routes recording Marsh Wren in Wyoming.
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 →
Seedskadee 21020242024
Carter 2820242018
Seedskadee820231993
Hunter Peak420171988
Tensleep220152010
Lingle219951995
Green River219841977
Ne Entrance119921992
Midvale120221994
Patrick Draw 6120122012
Cumberland119801978
Mckinnon119831983
Patrick Draw119801978
Lovell120052005
Patrick Draw 5120092009
Wilson119801980
Worland119971997
Harland Flat120242024
Boulder120241982
Moran120052005
Lamont119991999
Diamondville119811977
Mtn View120241980
Rock Springs119811979
Patrick Draw 2119821981

Marsh Wren Population Trend in Other States

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

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