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

American Bittern Population Trend in Montana

All statesWetland birds

American Bittern in Montana has edged down: down 13% on the route-weighted index since 1970.

-13%Since 1970TrendPercent 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 →
19Routes 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 →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Bittern Trends in MontanaNotable 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 American Bittern in Montana. See the full index history below.

American Bittern Population Forecast in Montana

If the recent trend holds, American Bittern in Montana is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±111.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.1595% 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 →
±111.1%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, American Bittern in Montana is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±111.1%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.010.000.15
20260.000.000.15
20270.000.000.15
20280.000.000.15
20290.000.000.15

American Bittern Survey Routes in Montana

Routes recording American Bittern in Montana.
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 →
Webster320232003
Kalispell220241968
Ester Lake220232016
Westby220232023
St Mary119951976
Flatwillow 2120182018
Cleveland120171979
Malta120231976
Redstone119791976
Roy120192019
Brusett119821982
Ingomar119801980
St Xavier119961996
Powderville119741970
Albion120082008
Beaverhead120241986
Winnett120232018
Lindsay120182018
Pablo Res.119951995

American Bittern Population Trend in Other States

alaskacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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