BirdAnalyst
Species · California · BBS 2025 Release · 1966–2024

Pinyon Jay Population Trend in California

All statesGeneralists

Pinyon Jay in California has surged: up 84% on the route-weighted index since 1970.

+84%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 →
34Routes 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 Pinyon Jay Trends in CaliforniaNotable 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 →

Pinyon Jay has surged in California: up 84% on the route-weighted index since 1970.

Pinyon Jay Population Forecast in California

If the recent trend holds, Pinyon Jay in California is projected to rise about 84% by 2029 — from 0.43 in 2024 to a central estimate of 0.79 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±97%, with 100% of held-out values landing inside the 95% band.

+84%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 →
0.79Projected 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 →
0.00–1.695% 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 →
±97%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, Pinyon Jay in California is projected to rise about 84% by 2029 — from 0.43 in 2024 to a central estimate of 0.79 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±97%, 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 →
20250.750.001.6
20260.760.001.6
20270.770.001.6
20280.780.001.6
20290.790.001.6

Pinyon Jay Survey Routes in California

Routes recording Pinyon Jay in California.
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 →
Crowley Lake3720041973
Deep Springs2220121972
Woodlands2020242016
Bridgeport1519741973
Anza1519761974
Benton1320241975
Bodie720241982
Death Valley719941994
Ravendale620011990
Nubieber520072003
Clear Lk Res520161975
Lockwood Val520031970
Lake Hemet419861974
Cholla Gard.320121995
Pine Mountain320161998
Mt Pinos319941974
Green Valley220221970
Dardanelle219991999
Big Pine220231968
Little Truckee219971997
Davis Creek220001990
Crestview220192004
Big Bear219791969
Anza 2220172006
Cima219911970

Pinyon Jay Population Trend in Other States

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