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

Rock Wren Population Trend in Washington

All statesForest birds

Rock Wren in Washington has surged: up 94% on the route-weighted index since 1970.

+94%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 →
50Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Rock Wren 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 →

Rock Wren has surged in Washington: up 94% on the route-weighted index since 1970.

Rock Wren Population Forecast in Washington

If the recent trend holds, Rock Wren in Washington is projected to stay roughly flat through 2030, near 0.87 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±58.1%, with 100% of held-out values landing inside the 95% band.

-7%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 →
0.87Projected 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 →
0.00–1.895% 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 →
±58.1%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, Rock Wren in Washington is projected to stay roughly flat through 2030, near 0.87 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±58.1%, 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 →
20260.850.001.8
20270.860.001.8
20280.860.001.8
20290.870.001.8
20300.870.001.8

Rock Wren Survey Routes in Washington

Routes recording Rock Wren 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 →
Moses Coulee1420251993
Walla Walla919931993
Lake Chelan920251988
Yakima720251993
Ewan 2520252024
Prescott520151985
Keller320061969
Asotin320251971
Ellensburg320251985
Malden320242024
Harwood319961993
Hatton319941992
L Pend O Nwr219961996
Winthrop220121989
Sulphur220211995
Pomeroy220092000
Twisp120241969
Brewster120151977
Chewelah119961977
Selah120252003
Arid Land Er119891988
Turnbull Nwr120171995
Ardenvoir119871970
Harrington120031984
Reardan120241968

Rock Wren Population Trend in Other States

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