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

Green-winged Teal Population Trend in Nevada

All statesWaterfowl

Green-winged Teal in Nevada has fallen sharply: down 51% on the route-weighted index since 1973.

-51%Since 1973TrendPercent 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 →
14Routes 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 →
32YearsYears 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 NevadaNotable 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 Nevada: down 51% on the route-weighted index since 1973.

Green-winged Teal Population Forecast in Nevada

If the recent trend holds, Green-winged Teal in Nevada is projected to fall about 34% by 2029 — from 0.21 in 2024 to a central estimate of 0.14 (95% range 0.00–0.88). A 5-year backtest shows a typical error of ±451.3%, with 100% of held-out values landing inside the 95% band.

-34%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 →
0.14Projected 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 →
0.00–0.8895% 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 →
±451.3%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 Nevada is projected to fall about 34% by 2029 — from 0.21 in 2024 to a central estimate of 0.14 (95% range 0.00–0.88). A 5-year backtest shows a typical error of ±451.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.170.000.91
20260.160.000.90
20270.150.000.90
20280.150.000.89
20290.140.000.88

Green-winged Teal Survey Routes in Nevada

Routes recording Green-winged Teal in Nevada.
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 →
Dobbin Creek820141968
Gardnerville 2520242018
Bald Mtn.220191992
Cortez219711968
Walker Can219811981
Toiyabe Nf220162016
Eureka220021973
Midas120162016
Dinner Sta119931973
Ranchogrande120081991
Virgin Creek120141997
Charleston Reservoir120242024
Illipah120171998
Ruby Valley 2120052005

Green-winged Teal Population Trend in Other States

alaskaarizonacaliforniacoloradoidahoillinoisindianaiowakansasmainemichiganminnesotamissourimontananebraskanew-hampshirenew-mexiconew-yorknorth-dakotaoklahomaoregonpennsylvaniasouth-dakotatexasutahvermontwashingtonwisconsinwyoming

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