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

American Goshawk Population Trend in California

All statesGeneralists

American Goshawk in California has declined: down 37% on the route-weighted index since 1979.

-37%Since 1979TrendPercent 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 →
34Routes 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 →
34YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Goshawk 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 American Goshawk in California. See the full index history below.

American Goshawk Population Forecast in California

If the recent trend holds, American Goshawk in California is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±117.4%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.02Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0495% 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 →
±117.4%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, American Goshawk in California is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±117.4%, with 100% of held-out values landing inside the 95% band.19742028
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 →
20240.020.000.04
20250.020.000.04
20260.020.000.04
20270.020.000.04
20280.020.000.04

American Goshawk Survey Routes in California

Routes recording American Goshawk 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 →
Kelso Valley120102010
Honeydew120122012
Eagle Lake120211978
Westville120222018
Dirigio120062000
Tionesta120192019
Crowder Flat120052002
Madeline119981998
Burnt Ranch120071998
Tuolumne Grove120112011
Meadow Valley120172017
Little Truckee120012001
Pollock Pines120142014
Coulterville120122012
Pine Mountain120032003
Macdoel120172017
Cecilville120032003
Offield Mtn119781978
Mt Shasta120121990
Hay Fork120042004
Friday Ridge120032003
Butte Meadow119801980
Genesee119931993
Chaos Crater120001990
Riverton120122010

American Goshawk Population Trend in Other States

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