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

House Finch Population Trend in California

All statesGeneralists

House Finch in California has declined: down 35% on the route-weighted index since 1970.

-35%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 →
236Routes 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 House Finch 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 House Finch in California. See the full index history below.

House Finch Population Forecast in California

If the recent trend holds, House Finch in California is projected to fall about 46% by 2030 — from 37 in 2025 to a central estimate of 20 (95% range 7.1–33). A 5-year backtest shows a typical error of ±49.5%, with 0% of held-out values landing inside the 95% band.

-46%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 →
20Projected 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 →
7.1–3395% 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 →
±49.5%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, House Finch in California is projected to fall about 46% by 2030 — from 37 in 2025 to a central estimate of 20 (95% range 7.1–33). A 5-year backtest shows a typical error of ±49.5%, with 0% 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 →
2026228.734
2027218.334
2028217.934
2029207.533
2030207.133

House Finch Survey Routes in California

Routes recording House Finch 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 →
Colma26519721968
Oroville20720251972
Parkfield20020251968
Hughson18820251968
Dorris18120191972
Caruthers17419871972
Lockwood15820251972
Joshua Tree15420021970
Poway15319801973
Tres Pinos 215320112005
Greenfield14720251973
Moreno13820251968
Tranquillity13820241972
S Catalina13320251988
Santa Cruz I12919881988
Pennington12720251971
Gravesboro12119951968
Harbor Lake 211820242014
Westley11320251972
Willow Spgs11219811968
Sisquoc11120141970
Tres Pinos11020031968
Collegeville 210820232007
Calif City10620151977
San Ysidro9320191973

House Finch Population Trend in Other States

alabamaarizonaarkansascoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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