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

Green-winged Teal Population Trend in Washington

All statesWaterfowl

Green-winged Teal in Washington has fallen sharply: down 62% on the route-weighted index since 1979.

-62%Since 1979TrendPercent 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 →
28Routes 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 →
35YearsYears 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 WashingtonNotable 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 Washington: down 62% on the route-weighted index since 1979.

Green-winged Teal Population Forecast in Washington

If the recent trend holds, Green-winged Teal in Washington is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±130.5%, 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 →
0.00–0.2095% 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 →
±130.5%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 Washington is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±130.5%, with 100% of held-out values landing inside the 95% band.19722029
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 →
20250.050.000.21
20260.050.000.20
20270.040.000.20
20280.040.000.20
20290.040.000.20

Green-winged Teal Survey Routes in Washington

Routes recording Green-winged Teal in Washington.
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 →
Harrington1220001984
Nighthawk820191999
Wapato619901990
Columbia Nwr420212005
Tonasket420131986
Bay View420062006
Chewelah319901990
Moses Coulee319971997
Turnbull Nwr220181993
Moses Lake219781978
Glacier220062006
Twin Lakes219911991
South Elma219841984
Carlton220002000
L. Wenatchee220022002
Carnation220052005
Warm Beach119721972
Twisp119801980
Brewster120111978
Reardan120191996
Cusick120042004
Wilbur120161983
Mendota119791979
Richland120182018
Keystone120021999

Green-winged Teal Population Trend in Other States

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