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

American Wigeon Population Trend in Montana

All statesWaterfowl

American Wigeon in Montana has declined: down 49% on the route-weighted index since 1971.

-49%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 →
59Routes 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 →
55YearsYears 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 stay roughly flat through 2029, near 0.49 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±34.4%, with 100% of held-out values landing inside the 95% band.

-9%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 →
0.49Projected 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 →
0.00–1.995% 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 →
±34.4%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 stay roughly flat through 2029, near 0.49 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±34.4%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.560.001.9
20260.550.001.9
20270.530.001.9
20280.510.001.9
20290.490.001.9

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 →
Dinosaurs H.M.2820212019
Hay Lake1520191989
Shelby1120192015
Sunburst1020071970
Malta620241975
Two Dot620241981
Brandenberg620192019
Glen420172005
Polson420001980
Highwood420171977
Roy420231991
Shawmut420241979
Chinook420232015
Ester Lake420242015
Sun River420192019
Virgelle320241979
Glasgow320241972
Flatwillow319911974
Ingomar320241970
East Glacier Park320222019
Raynesford320242019
Wheat Basin320232017
Whitlash320182009
Kalispell220161971
St Mary220081973

American Wigeon Population Trend in Other States

alaskacaliforniacoloradoidahokansasmichiganminnesotanebraskanevadanew-mexiconorth-dakotaohiooregonpennsylvaniasouth-dakotatexasutahwashingtonwisconsinwyoming

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