BirdAnalyst
Species · California · BBS 2026 Release · 1966–2025

Oak Titmouse Population Trend in California

All statesForest birds

Oak Titmouse in California has increased: up 47% on the route-weighted index since 1970.

+47%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 →
156Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Oak Titmouse 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 Oak Titmouse in California. See the full index history below.

Oak Titmouse Population Forecast in California

If the recent trend holds, Oak Titmouse in California is projected to stay roughly flat through 2030, near 5.7 (95% range 3.7–7.6). A 5-year backtest shows a typical error of ±7%, with 100% of held-out values landing inside the 95% band.

+4%Change by 2030TrendPercent 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 →
5.7Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
3.7–7.695% 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 →
±7%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, Oak Titmouse in California is projected to stay roughly flat through 2030, near 5.7 (95% range 3.7–7.6). A 5-year backtest shows a typical error of ±7%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20265.73.77.6
20275.73.77.6
20285.73.77.6
20295.73.77.6
20305.73.77.6

Oak Titmouse Survey Routes in California

Routes recording Oak Titmouse 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 →
White River8019921972
Auburn5819801969
Silver City5420131973
Sisquoc5020141970
Lockwood4420251972
Jackson4319921972
Tres Pinos 24220112005
Bass Lake3820191972
Rumsey3720081969
Orange Cove3620161972
Carmel Val3620251973
Coyote3620251972
Lake Berryessa3220252023
Yokohl Val3019971972
Adelaida2920251970
Elsinore Mtn2820251970
South Lake2720062006
Iron Gate2520191988
Colma2419721968
Red Bluff2320251968
Santa Ynez2320191969
Lake Success2319961972
Moraga2320251972
Mark West2220251972
Morro Bay2120191973

Oak Titmouse Population Trend in Other States

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Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.