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Species · Arizona · BBS 2025 Release · 1966–2024

Woodhouse's Scrub-Jay Population Trend in Arizona

All statesGeneralists

Woodhouse's Scrub-Jay in Arizona has risen sharply: up 62% on the route-weighted index since 1970.

+62%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 →
45Routes 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 Woodhouse's Scrub-Jay Trends in ArizonaNotable 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 risen sharply in Arizona: up 61% on the route-weighted index since 1970.

Woodhouse's Scrub-Jay Population Forecast in Arizona

If the recent trend holds, Woodhouse's Scrub-Jay in Arizona is projected to stay roughly flat through 2029, near 1.7 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±20.6%, with 100% of held-out values landing inside the 95% band.

+3%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 →
1.7Projected 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 →
0.00–3.495% 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 →
±20.6%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 Arizona is projected to stay roughly flat through 2029, near 1.7 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±20.6%, 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 →
20251.70.023.4
20261.70.013.4
20271.70.003.4
20281.70.003.4
20291.70.003.4

Woodhouse's Scrub-Jay Survey Routes in Arizona

Routes recording Woodhouse's Scrub-Jay in Arizona.
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 →
Skull Valley3020241996
Pinetop1220221993
Rucker920001993
Zeniff819841968
Sunizona819971988
Black Mesa719921988
Bartlett Res720241992
Cow Springs620221992
Mt Trumbull519791979
Prescott520221974
Aztec Peak519781974
Portal420241975
Dragoon420091993
Blue419911974
Forest Lakes420241992
Redington420231993
Yampai319771969
Rose Wells319771968
Hunt320181976
Tsaile320221996
Carr Mtn320241985
Round Rock219701970
Mormon Lake219751968
Page220192011
Castle Butte220051994

Woodhouse's Scrub-Jay Population Trend in Other States

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