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

Canada Jay Population Trend in California

All statesGeneralists

Canada Jay in California has declined: down 42% on the route-weighted index since 1977.

-42%Since 1977TrendPercent 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 →
13Routes 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 →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Canada 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 →

No notable trend signals for Canada Jay in California. See the full index history below.

Canada Jay Population Forecast in California

If the recent trend holds, Canada Jay in California is projected to stay roughly flat through 2026, near 0.03 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±155%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2026TrendPercent 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 →
0.03Projected 2026 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0795% 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 →
±155%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, Canada Jay in California is projected to stay roughly flat through 2026, near 0.03 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±155%, with 100% of held-out values landing inside the 95% band.19732026
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 →
20220.030.000.07
20230.030.000.07
20240.030.000.07
20250.030.000.07
20260.030.000.07

Canada Jay Survey Routes in California

Routes recording Canada 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 →
Fall River Mills719981998
Medicine Mtn.520142000
Navarro519731973
Redwood N.P. 2520122012
Tionesta320192008
Offield Mtn220092009
Junction Cty119801980
Ship Mtn.120142014
Bartle120211983
Rio Dell120121977
Mt Shasta120011976
Chester119991999
Goumaz120102001

Canada Jay Population Trend in Other States

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