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Species · Colorado · BBS 2026 Release · 1966–2025

Woodhouse's Scrub-Jay Population Trend in Colorado

All statesForest birds

Woodhouse's Scrub-Jay in Colorado has surged: up 90% on the route-weighted index since 1970.

+90%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 →
68Routes 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 Woodhouse's Scrub-Jay Trends in ColoradoNotable 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 →

Woodhouse's Scrub-Jay has surged in Colorado: up 90% on the route-weighted index since 1970.

Woodhouse's Scrub-Jay Population Forecast in Colorado

If the recent trend holds, Woodhouse's Scrub-Jay in Colorado is projected to rise about 13% by 2030 — from 0.78 in 2025 to a central estimate of 0.88 (95% range 0.28–1.5). A 5-year backtest shows a typical error of ±9.4%, with 100% of held-out values landing inside the 95% band.

+13%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 →
0.88Projected 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 →
0.28–1.595% 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 →
±9.4%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, Woodhouse's Scrub-Jay in Colorado is projected to rise about 13% by 2030 — from 0.78 in 2025 to a central estimate of 0.88 (95% range 0.28–1.5). A 5-year backtest shows a typical error of ±9.4%, 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 →
20260.850.251.4
20270.850.261.5
20280.860.271.5
20290.870.271.5
20300.880.281.5

Woodhouse's Scrub-Jay Survey Routes in Colorado

Routes recording Woodhouse's Scrub-Jay in Colorado.
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 →
Browns Park6320062006
Walsenburg1920251994
Cortez 21020172010
Animas920041996
Mesaverde Np820251996
Falfa820251971
Delta720211974
Animas 2620252005
Paonia620251993
Ludlow620251998
Harmony420251981
Lay420232022
Baxter Pass420241995
Buffalo Park420232023
Douglas Pass320241982
Rosevale320242010
Gribbles Prk320251995
Angora320251998
Rifle Falls320211998
Maybell220241973
Dolores219871969
Pagosa Spgs219781968
Rio Grnds Rs219911991
Wilson Creek220241990
Dinosaur220251995

Woodhouse's Scrub-Jay Population Trend in Other States

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