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

Turkey Vulture Population Trend in California

All statesBirds of prey

Turkey Vulture in California has surged: up 101% on the route-weighted index since 1970.

+101%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 →
232Routes 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 Turkey Vulture 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 →

Turkey Vulture has surged in California: up 101% on the route-weighted index since 1970.

Turkey Vulture Population Forecast in California

If the recent trend holds, Turkey Vulture in California is projected to stay roughly flat through 2030, near 5.6 (95% range 4.4–6.9). A 5-year backtest shows a typical error of ±10.7%, with 100% of held-out values landing inside the 95% band.

+1%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 →
5.6Projected 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 →
4.4–6.995% 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 →
±10.7%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, Turkey Vulture in California is projected to stay roughly flat through 2030, near 5.6 (95% range 4.4–6.9). A 5-year backtest shows a typical error of ±10.7%, with 100% 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 →
20265.44.16.7
20275.54.26.7
20285.54.36.8
20295.64.36.8
20305.64.46.9

Turkey Vulture Survey Routes in California

Routes recording Turkey Vulture 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 →
Iron Gate4920191988
Honeydew4720171968
Coyote4320251973
Tres Pinos 23520112005
Ono3220121984
Sisquoc3020141991
Glenn3020251978
Hughson2620251968
Mark West2420251972
Macdoel2320191972
Adelaida2220251970
Tres Pinos1920021968
Ravendale1920251973
Shasta Lake1820251972
Jofegan 21720252024
Folsom1720251984
Yolla Bolly1720251973
South Lake1720062006
Tracy 21720232010
Parkfield1620251968
Ingalls1620251973
Carmel Val1620251973
Hollister 21620242012
Red Bluff1520251968
Blythe1520031973

Turkey Vulture 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.