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

Green-winged Teal Population Trend in Idaho

All statesWaterfowl

Green-winged Teal in Idaho has fallen sharply: down 65% on the route-weighted index since 1981.

-65%Since 1981TrendPercent 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 →
31Routes 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 →
41YearsYears 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 IdahoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Green-winged Teal has fallen sharply in Idaho: down 65% on the route-weighted index since 1981.

Green-winged Teal Population Forecast in Idaho

If the recent trend holds, Green-winged Teal in Idaho is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±39.4%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.04Projected 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 →
0.00–0.2695% 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 →
±39.4%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, Green-winged Teal in Idaho is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±39.4%, with 100% of held-out values landing inside the 95% band.19772029
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 →
20250.060.000.28
20260.060.000.27
20270.050.000.27
20280.050.000.27
20290.040.000.26

Green-winged Teal Survey Routes in Idaho

Routes recording Green-winged Teal in Idaho.
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 →
Sawtooth City 2420172015
Kyle Canyon319981998
Cedar Hill320221998
Mivoden219771977
Twin Buttes219991999
Challis220221986
Leadore220221983
Springfield219811977
Henry219791977
Daniels Res219941993
Preston220042004
Nezperce Nf219921992
Sawtooth Cty220091988
Pasadena Val219941989
Blackft Res120161984
Naples120231988
Lolo Pass120012001
Baker119921982
Cascade119841984
Squirrel119771977
Centerville120071996
Craters119841984
Triangle120141998
Magic Mtn120141992
Joel120132004

Green-winged Teal Population Trend in Other States

alaskaarizonacaliforniacoloradoillinoisindianaiowakansasmainemichiganminnesotamissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-dakotaoklahomaoregonpennsylvaniasouth-dakotatexasutahvermontwashingtonwisconsinwyoming

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