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Species · Montana · BBS 2025 Release · 1966–2024

Green-winged Teal Population Trend in Montana

All statesWaterfowl

Green-winged Teal in Montana has edged down: down 24% on the route-weighted index since 1970.

-24%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 →
52Routes 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 →
48YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Green-winged Teal 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 Green-winged Teal in Montana. See the full index history below.

Green-winged Teal Population Forecast in Montana

If the recent trend holds, Green-winged Teal in Montana is projected to fall about 59% by 2029 — from 0.32 in 2024 to a central estimate of 0.13 (95% range 0.00–0.49). A 5-year backtest shows a typical error of ±211.1%, with 100% of held-out values landing inside the 95% band.

-59%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 →
0.13Projected 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 →
0.00–0.4995% 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 →
±211.1%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, Green-winged Teal in Montana is projected to fall about 59% by 2029 — from 0.32 in 2024 to a central estimate of 0.13 (95% range 0.00–0.49). A 5-year backtest shows a typical error of ±211.1%, 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 →
20250.140.000.51
20260.140.000.51
20270.140.000.50
20280.130.000.50
20290.130.000.49

Green-winged Teal Survey Routes in Montana

Routes recording Green-winged Teal 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 →
Powderville1819791979
Highwood1420161969
Sun River920242024
Hay Lake620191989
Savage619781978
Shawmut620232009
Glasgow519821979
Whitlash520172013
Webster420241980
Westby420242015
Lima420061996
Cleveland320231995
Redstone320132013
Forsyth320052005
Shelby320192015
Sunburst220021976
Virgelle220241993
Harlem219741974
Malta220161975
Glen220211977
Leroy220141988
Jordan220231968
Circle219891989
Flatwillow219941976
Winifred 2220242024

Green-winged Teal Population Trend in Other States

alaskaarizonacaliforniacoloradoidahoillinoisindianaiowakansasmainemichiganminnesotamissourinebraskanevadanew-hampshirenew-mexiconew-yorknorth-dakotaoklahomaoregonpennsylvaniasouth-dakotatexasutahvermontwashingtonwisconsinwyoming

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