BirdAnalyst
Species · Washington · BBS 2026 Release · 1966–2025

Mountain Bluebird Population Trend in Washington

All statesForest birds

Mountain Bluebird in Washington has surged: up 340% on the route-weighted index since 1970.

+340%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 →
34Routes 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 Mountain 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 →

Mountain Bluebird has surged in Washington: up 340% on the route-weighted index since 1970.

Mountain Bluebird Population Forecast in Washington

If the recent trend holds, Mountain Bluebird in Washington is projected to stay roughly flat through 2030, near 1.0 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±41.3%, with 100% of held-out values landing inside the 95% band.

+4%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 →
1.0Projected 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 →
0.00–2.295% 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 →
±41.3%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, Mountain Bluebird in Washington is projected to stay roughly flat through 2030, near 1.0 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±41.3%, with 100% 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 →
20260.990.002.2
20270.990.002.2
20281.000.002.2
20291.000.002.2
20301.00.002.2

Mountain Bluebird Survey Routes in Washington

Routes recording Mountain 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 →
Bickleton3020191980
Ellensburg2220251981
Pomeroy1620241992
Cloverland1220251993
Asotin1020251982
Rimrock519721969
Curlew520131992
Omak Creek420241996
Spring Lake320241985
Twisp220021971
Selah220232000
Keller220051968
Chewelah220191977
E. Mt. Adams220232023
Reardan219921969
Tonasket220151986
Waitsburg219941994
Deer Park219951995
L Pend O Nwr120221996
Ardenvoir119871969
Sullivan Lake 2120112001
Snowden119921986
Kendall120082008
Cusick120251994
Ronald119961975

Mountain Bluebird Population Trend in Other States

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