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

Western Bluebird Population Trend in Washington

All statesForest birds

Western Bluebird in Washington has surged: up 103% on the route-weighted index since 1970.

+103%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 →
39Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Western Bluebird 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 →

Western Bluebird has surged in Washington: up 103% on the route-weighted index since 1970.

Western Bluebird Population Forecast in Washington

If the recent trend holds, Western Bluebird in Washington is projected to stay roughly flat through 2029, near 1.2 (95% range 0.74–1.6). A 5-year backtest shows a typical error of ±17.7%, with 100% of held-out values landing inside the 95% band.

+10%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 →
1.2Projected 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 →
0.74–1.695% 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 →
±17.7%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, Western Bluebird in Washington is projected to stay roughly flat through 2029, near 1.2 (95% range 0.74–1.6). A 5-year backtest shows a typical error of ±17.7%, 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 →
20251.10.681.5
20261.10.701.5
20271.10.711.5
20281.10.721.6
20291.20.741.6

Western Bluebird Survey Routes in Washington

Routes recording Western Bluebird 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 →
Ellensburg2820241981
Pomeroy1920241992
Ewan 2620232023
Selah420122003
Turnbull Nwr320231993
Northport320181998
Lake Chelan320241988
Twisp220241983
Kamilche219871987
Ardenvoir219871985
Reardan220181968
Cougar220212021
Snowden220231971
Bickleton220181983
Tonasket220161988
Wilbur220221997
Ewan220021995
Nighthawk220231999
Hurricane Rg220212016
Harwood219931993
Omak Creek220241998
Laurier220211996
Cloverland220142014
Keller120071968
Chewelah120211977

Western Bluebird Population Trend in Other States

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