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

Red-shouldered Hawk Population Trend in California

All statesBirds of prey

Red-shouldered Hawk in California has surged: up 573% on the route-weighted index since 1970.

+573%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 →
130Routes 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 Red-shouldered 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 →

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-shouldered Hawk has surged in California: up 573% on the route-weighted index since 1970.

Red-shouldered Hawk Population Forecast in California

If the recent trend holds, Red-shouldered Hawk in California is projected to stay roughly flat through 2030, near 0.87 (95% range 0.64–1.1). A 5-year backtest shows a typical error of ±17%, with 80% of held-out values landing inside the 95% band.

+6%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 →
0.87Projected 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 →
0.64–1.195% 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 →
±17%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-shouldered Hawk in California is projected to stay roughly flat through 2030, near 0.87 (95% range 0.64–1.1). A 5-year backtest shows a typical error of ±17%, with 80% 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 →
20260.820.591.1
20270.830.601.1
20280.850.611.1
20290.860.631.1
20300.870.641.1

Red-shouldered Hawk Survey Routes in California

Routes recording Red-shouldered 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 →
Fairfax1520241978
Coyote820251995
Mark West620251973
Crescent Cty520251977
Jofegan 2520252024
Bass Lake520192007
San Ysidro520191977
Silver City520131978
Alderpoint520121975
Harbor Lake 2520242014
Lake Success419961980
Navarro420111972
Carmel Val420251974
Tres Pinos 2420112005
Collegeville 2420142009
Calpella319861973
Hughson320251979
Orange Cove320161976
Morro Bay320191974
Point Reyes320251970
Sawmill Mtn320131973
El Toro319991973
Lake Berryessa320252024
Elizabeth Lk320161976
Higgins Corn320251990

Red-shouldered Hawk Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawashingtonwest-virginiawisconsin

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