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

Blue-winged Teal Population Trend in Montana

All statesWaterfowl

Blue-winged Teal in Montana has edged up: up 15% on the route-weighted index since 1970.

+15%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 →
70Routes 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 Blue-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 Blue-winged Teal in Montana. See the full index history below.

Blue-winged Teal Population Forecast in Montana

If the recent trend holds, Blue-winged Teal in Montana is projected to fall about 20% by 2030 — from 0.64 in 2025 to a central estimate of 0.51 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±56.7%, with 80% of held-out values landing inside the 95% band.

-20%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 →
0.51Projected 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 →
±56.7%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, Blue-winged Teal in Montana is projected to fall about 20% by 2030 — from 0.64 in 2025 to a central estimate of 0.51 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±56.7%, with 80% of held-out values landing inside the 95% band.19682030
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 →
20260.570.001.9
20270.550.001.9
20280.540.001.9
20290.530.001.9
20300.510.001.9

Blue-winged Teal Survey Routes in Montana

Routes recording Blue-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 →
Westby3020252015
Hay Lake820191990
Cleveland720231979
Webster720241978
Lambert720252025
Jordan620241968
Locate620241982
Pablo Res.520231995
Malta420241975
Polson419991988
Augusta420251976
Circle420231969
Ingomar420041970
East Glacier Park420212019
Ester Lake420242015
Saco420192019
Willow Creek 2320011982
Great Falls320231972
Highwood320231968
Forsyth320181995
Albion320141982
Winifred320232023
Jordan South320242016
Coleman Coulee320192018
Wise River320182018

Blue-winged Teal Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradodelawarefloridaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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