BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Woodhouse's Scrub-Jay

CorvidaeForest birdsAphelocoma woodhouseii

Woodhouse's Scrub-Jay has held roughly steady: up 4% on the route-weighted index since 1970.

+4%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 →
299RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Woodhouse's Scrub-Jay

The Woodhouse's Scrub-Jay (Aphelocoma woodhouseii) is a North American member of the Crows, Jays & Magpies (Corvidae). In this analysis it is grouped with the forest birds.

Size
10–27.5 in long (25–70 cm) — a medium to large songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 299 Breeding Bird Survey routes across 9 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Corvidae · Forest birds

Notable Woodhouse's Scrub-Jay TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Woodhouse's Scrub-Jay. See the full index history below.

Woodhouse's Scrub-Jay Population Forecast

If the recent trend holds, Woodhouse's Scrub-Jay is projected to rise about 43% by 2029 — from 0.12 in 2024 to a central estimate of 0.18 (95% range 0.09–0.26). A 5-year backtest shows a typical error of ±43.4%, with 100% of held-out values landing inside the 95% band.

+43%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 →
0.18Projected 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 →
0.09–0.2695% 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 →
±43.4%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 is projected to rise about 43% by 2029 — from 0.12 in 2024 to a central estimate of 0.18 (95% range 0.09–0.26). A 5-year backtest shows a typical error of ±43.4%, 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 →
20250.170.080.26
20260.170.090.26
20270.170.090.26
20280.170.090.26
20290.180.090.26

Where the Woodhouse's Scrub-Jay Is Detected

BBS routes recording Woodhouse's Scrub-Jay, sized by most recent count.

Woodhouse's Scrub-Jay Population Trend by State

Woodhouse's Scrub-Jay population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+62%197045
California-8%19835
Colorado+110%197068
Idahoinsufficient datan/a2
Nevada-59%197019
New Mexico-61%197055
Texas-6%197133
Utah-88%198170
Wyominginsufficient datan/a2

Woodhouse's Scrub-Jay Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Woodhouse's Scrub-Jay population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Great Basin-31%197036
Northern Rockies+247%19935
Southern Rockies / Colorado Plateau-75%1970168
Shortgrass Prairie-29%197813
Central Mixed Grass Prairie+23%19857
Edwards Plateau+92%197115
Sonoran and Mojave Deserts-54%19835
Sierra Madre Occidental+618%197130
Chihuahuan Desert-71%197020

Woodhouse's Scrub-Jay Conservation Status

Our route-weighted index shows it up about 4% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.