BirdAnalyst
Species · Montana · BBS 2026 Release · 1966–2025

American Wigeon Population Trend in Montana

All statesWaterfowl

American Wigeon in Montana has declined: down 41% on the route-weighted index since 1971.

-41%Since 1971TrendPercent 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 →
62Routes 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 →
56YearsYears 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 Wigeon 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 Wigeon in Montana. See the full index history below.

American Wigeon Population Forecast in Montana

If the recent trend holds, American Wigeon in Montana is projected to fall about 22% by 2030 — from 0.61 in 2025 to a central estimate of 0.48 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±34%, with 100% of held-out values landing inside the 95% band.

-22%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 →
0.48Projected 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 →
0.00–1.995% 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 →
±34%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 Wigeon in Montana is projected to fall about 22% by 2030 — from 0.61 in 2025 to a central estimate of 0.48 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±34%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.550.001.9
20270.530.001.9
20280.510.001.9
20290.500.001.9
20300.480.001.9

American Wigeon Survey Routes in Montana

Routes recording American Wigeon 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 →
Hay Lake1520191989
Shelby1120192015
Sunburst1020071970
Ester Lake820252015
Two Dot720251981
Malta620241975
Brandenberg620192019
Roy520251991
Shawmut520251979
Glen420172005
Polson420001980
Highwood420171977
Webster420251978
Sun River420192019
Glasgow320241972
Flatwillow319911974
East Glacier Park320222019
Philipsburg320252025
Wheat Basin320232017
Whitlash320182009
Kalispell220161971
St Mary220081973
Virgelle220251979
Oswego220241978
Redstone220131972

American Wigeon Population Trend in Other States

alaskacaliforniacoloradoidahokansasmichiganminnesotanebraskanevadanew-mexiconorth-dakotaohiooregonpennsylvaniasouth-dakotatexasutahwashingtonwisconsinwyoming

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