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Species · California · BBS 2025 Release · 1966–2024

Black-capped Chickadee Population Trend in California

All statesForest birds

Black-capped Chickadee in California has surged: up 119% on the route-weighted index since 1981.

+119%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 →
10Routes 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 →
37YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-capped Chickadee 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 Black-capped Chickadee in California. See the full index history below.

Black-capped Chickadee Population Forecast in California

If the recent trend holds, Black-capped Chickadee in California is projected to stay roughly flat through 2029, near 0.08 (95% range 0.01–0.15). A 5-year backtest shows a typical error of ±295.7%, with 40% of held-out values landing inside the 95% band.

n/aChange 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 →
0.08Projected 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 →
0.01–0.1595% 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 →
±295.7%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, Black-capped Chickadee in California is projected to stay roughly flat through 2029, near 0.08 (95% range 0.01–0.15). A 5-year backtest shows a typical error of ±295.7%, with 40% of held-out values landing inside the 95% band.19752029
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 →
20250.070.000.14
20260.070.000.14
20270.070.000.14
20280.070.000.15
20290.080.010.15

Black-capped Chickadee Survey Routes in California

Routes recording Black-capped Chickadee 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 →
Navarro519971997
Horse Creek420191992
Crescent Cty320241981
Iron Gate320191991
Korbel319971997
Fairfax319901990
Bartle220172004
Macdoel219771977
Dorris120122012
Woodfords119751975

Black-capped Chickadee Population Trend in Other States

alaskacoloradoconnecticutidahoillinoisindianaiowakansasmainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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