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Species · California · BBS 2026 Release · 1966–2025

Mountain Chickadee Population Trend in California

All statesForest birds

Mountain Chickadee in California has increased: up 32% on the route-weighted index since 1970.

+32%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 →
122Routes 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 Mountain 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 Mountain Chickadee in California. See the full index history below.

Mountain Chickadee Population Forecast in California

If the recent trend holds, Mountain Chickadee in California is projected to rise about 98% by 2030 — from 3.8 in 2025 to a central estimate of 7.4 (95% range 4.4–10). A 5-year backtest shows a typical error of ±88.1%, with 20% of held-out values landing inside the 95% band.

+98%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 →
7.4Projected 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 →
4.4–1095% 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 →
±88.1%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, Mountain Chickadee in California is projected to rise about 98% by 2030 — from 3.8 in 2025 to a central estimate of 7.4 (95% range 4.4–10). A 5-year backtest shows a typical error of ±88.1%, with 20% 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 →
20267.34.310
20277.34.310
20287.44.310
20297.44.410
20307.44.410

Mountain Chickadee Survey Routes in California

Routes recording Mountain 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 →
Valyermo6520191970
Goumaz6120111997
Hackamore6020102000
Pine Mountain5520171997
Medicine Mtn.4820212000
Chilcoot4520241998
Lassen Park4419891972
Last Chance4420191993
Mt Laguna3819871970
Greenhorn Mt3720081971
Eagle Lake3420251969
Little Truckee3320251997
Lumberyard3220251976
Woodlands3120242012
Crowder Flat3120192002
Meadow Valley3020251999
Lake Hemet2919861970
Macdoel2920191972
Chester2920171997
Big Bear2819861969
Fallsvale2819811970
Hat Creek2820181973
Bartle2720211972
Lakeshore2720241972
Johnsville2620251975

Mountain Chickadee Population Trend in Other States

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