BirdAnalyst
Species · California · BBS 2025 Release · 1966–2024

Red-tailed Hawk Population Trend in California

All statesGeneralists

Red-tailed Hawk 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 →
259Routes 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-tailed Hawk 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 Red-tailed Hawk in California. See the full index history below.

Red-tailed Hawk Population Forecast in California

If the recent trend holds, Red-tailed Hawk in California is projected to stay roughly flat through 2029, near 3.8 (95% range 3.1–4.5). A 5-year backtest shows a typical error of ±10.8%, with 80% of held-out values landing inside the 95% band.

-4%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 →
3.8Projected 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 →
3.1–4.595% 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 →
±10.8%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-tailed Hawk in California is projected to stay roughly flat through 2029, near 3.8 (95% range 3.1–4.5). A 5-year backtest shows a typical error of ±10.8%, with 80% 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 →
20253.73.04.4
20263.73.04.4
20273.83.04.5
20283.83.14.5
20293.83.14.5

Red-tailed Hawk Survey Routes in California

Routes recording Red-tailed Hawk 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 →
Athlone3320071972
Dorris2920191972
Macdoel2520191972
Parkfield2420241968
Tres Pinos 22020112005
Likely1920241971
Oneals1820241972
Hughson1720241968
Hollister1420111974
Sanger1420242011
Lake Berryessa1320242023
Moraga1320241972
Ventucopa1220021975
Copperopolis1220241972
Moreno1120241968
Sisquoc1120141970
Ora Loma1120241973
Collegeville 21120232007
Mesa Grande920241970
Atwater920121971
Sattley920241972
Cedarville920241974
Coyote920241972
Livermore919911972
Goumaz920111997

Red-tailed Hawk Population Trend in Other States

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

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