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Species · California · BBS 2025 Release · 1966–2024

Red-breasted Nuthatch Population Trend in California

All statesForest birds

Red-breasted Nuthatch in California has surged: up 347% on the route-weighted index since 1970.

+347%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 →
137Routes 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 Red-breasted Nuthatch 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 →

Red-breasted Nuthatch has surged in California: up 347% on the route-weighted index since 1970.

Red-breasted Nuthatch Population Forecast in California

If the recent trend holds, Red-breasted Nuthatch in California is projected to rise about 81% by 2029 — from 3.6 in 2024 to a central estimate of 6.5 (95% range 4.3–8.7). A 5-year backtest shows a typical error of ±53.5%, with 40% of held-out values landing inside the 95% band.

+81%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 →
6.5Projected 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 →
4.3–8.795% 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 →
±53.5%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, Red-breasted Nuthatch in California is projected to rise about 81% by 2029 — from 3.6 in 2024 to a central estimate of 6.5 (95% range 4.3–8.7). A 5-year backtest shows a typical error of ±53.5%, with 40% 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 →
20256.24.08.4
20266.34.18.5
20276.44.28.6
20286.54.38.7
20296.54.38.7

Red-breasted Nuthatch Survey Routes in California

Routes recording Red-breasted Nuthatch 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 →
Lumberyard7420241976
Lassen Park4719891972
Westville4720241971
Goumaz3720111997
Pilot Creek3619961994
Medicine Mtn.3520212000
Hat Creek3420181973
South Fork Mtn3420222000
Dirigio3020141999
Meadow Valley2820241999
Mccloud2720211973
Lake Hemet 22619931992
Placerville2620241997
Forest Hill2420221997
Strawberry2420191999
Stonyford2420182015
Forest Hill 22320052005
Riverton2320231973
Chester2220171997
Butte Meadow2120141972
Downieville2120241975
Johnsville2020241975
Greenhorn Mt2020081971
Friday Ridge1820241994
Little Truckee1720231997

Red-breasted Nuthatch Population Trend in Other States

alaskaarizonacoloradoconnecticutidahoillinoisindianakansasmainemarylandmassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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