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Species · Utah · BBS 2025 Release · 1966–2024

Woodhouse's Scrub-Jay Population Trend in Utah

All statesGeneralists

Woodhouse's Scrub-Jay in Utah has collapsed: down 88% on the route-weighted index since 1981.

-88%Since 1981TrendPercent 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 →
70Routes 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 →
43YearsYears 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 UtahNotable 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 declinecomputed 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 collapsed in Utah: down 88% on the route-weighted index since 1981.

Woodhouse's Scrub-Jay Population Forecast in Utah

If the recent trend holds, Woodhouse's Scrub-Jay in Utah is projected to fall about 100% by 2029 — from 0.97 in 2024 to a central estimate of 0.00 (95% range 0.00–6.4). A 5-year backtest shows a typical error of ±225.8%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–6.495% 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 →
±225.8%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 Utah is projected to fall about 100% by 2029 — from 0.97 in 2024 to a central estimate of 0.00 (95% range 0.00–6.4). A 5-year backtest shows a typical error of ±225.8%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.000.006.4
20260.000.006.4
20270.000.006.4
20280.000.006.4
20290.000.006.4

Woodhouse's Scrub-Jay Survey Routes in Utah

Routes recording Woodhouse's Scrub-Jay in Utah.
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 →
Bonanza4220131993
Newcastle2220221997
Moon Lake1619941994
Main Canyon920241988
Alton 2820222021
Castle Dale720172015
Shivwitz720241993
Fayette520211992
Gooseberry520241994
La Sal 3520242007
Book Ridge420242003
Wellington 2420072005
Ferron420092001
Monticello420242000
Moquith Mtn420241987
Castleton319851969
Canyonlands320061991
Alton320191997
Glen Canyon320231996
Blanding320241997
Arches Np220051989
Dragerton219971997
Willow Creek220041986
La Sal 2220062003
Hanksville219931993

Woodhouse's Scrub-Jay Population Trend in Other States

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