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Species · Washington · BBS 2026 Release · 1966–2025

Warbling Vireo Population Trend in Washington

All statesForest birds

Warbling Vireo in Washington has surged: up 114% on the route-weighted index since 1970.

+114%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 →
88Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Warbling Vireo 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 increasecomputed 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 →

Warbling Vireo has surged in Washington: up 114% on the route-weighted index since 1970.

Warbling Vireo Population Forecast in Washington

If the recent trend holds, Warbling Vireo in Washington is projected to stay roughly flat through 2030, near 12 (95% range 8.3–15). A 5-year backtest shows a typical error of ±11.1%, with 80% of held-out values landing inside the 95% band.

+1%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 →
12Projected 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 →
8.3–1595% 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 →
±11.1%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, Warbling Vireo in Washington is projected to stay roughly flat through 2030, near 12 (95% range 8.3–15). A 5-year backtest shows a typical error of ±11.1%, 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 →
2026117.614
2027117.815
2028118.015
2029118.115
2030128.315

Warbling Vireo Survey Routes in Washington

Routes recording Warbling Vireo 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 →
Cougar8820231968
Montesand5720241987
Kamilche4120251968
Kendall3620251981
Spring Lake3620251985
Pe Ell3620251993
Newhalem3320251968
Rimrock3120251968
Ozette3020251971
E. Mt. Adams2820251995
Cedar Falls2720141995
Blewett Pass2520251995
Mendota 32520252005
Cusick2120251982
Raymond 22120242022
Omak Creek1920241996
Twin Lakes1820251983
White Chuck1820251992
Ronald1620251973
Raymond1620211993
Mazama1520221993
South Elma1320241975
Lake Chelan1320251988
No Cascades1320191989
Snowden1220251981

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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