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

Blue-winged Teal Population Trend in Indiana

All statesWaterfowl

Blue-winged Teal in Indiana has edged down: down 21% on the route-weighted index since 1971.

-21%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 →
20Routes 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 →
30YearsYears 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 IndianaNotable 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 Indiana. See the full index history below.

Blue-winged Teal Population Forecast in Indiana

If the recent trend holds, Blue-winged Teal in Indiana is projected to fall about 23% by 2029 — from 0.09 in 2024 to a central estimate of 0.07 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±126.1%, with 100% of held-out values landing inside the 95% band.

-23%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 →
0.07Projected 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 →
0.00–0.4095% 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 →
±126.1%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, Blue-winged Teal in Indiana is projected to fall about 23% by 2029 — from 0.09 in 2024 to a central estimate of 0.07 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±126.1%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.080.000.41
20260.080.000.41
20270.070.000.41
20280.070.000.41
20290.070.000.40

Blue-winged Teal Survey Routes in Indiana

Routes recording Blue-winged Teal in Indiana.
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 →
Brookville419971997
Packertown 2320172017
Indiana Dune220242021
Packertown219681968
Fowler219971997
Brazil219781978
Crown Point220182015
Cuba220242019
Gary119841980
Hebron119961981
South Bend119711971
Kewanna119911991
Columbia Cty120221982
Ellis119831966
W Lafayette119951993
Kankakee Sands120242002
Tipton119741974
Shelbyville119981997
Decatur120192019
Portage120042002

Blue-winged Teal Population Trend in Other States

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

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