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

Turkey Vulture Population Trend in California

All statesGeneralists

Turkey Vulture in California has surged: up 85% on the route-weighted index since 1970.

+85%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 →
229Routes 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 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 85% 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 rise about 14% by 2029 — from 4.9 in 2024 to a central estimate of 5.6 (95% range 4.3–6.8). A 5-year backtest shows a typical error of ±11.4%, with 100% of held-out values landing inside the 95% band.

+14%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 →
5.6Projected 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 →
4.3–6.895% 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 →
±11.4%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, Turkey Vulture in California is projected to rise about 14% by 2029 — from 4.9 in 2024 to a central estimate of 5.6 (95% range 4.3–6.8). A 5-year backtest shows a typical error of ±11.4%, with 100% 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 →
20255.34.16.6
20265.44.16.6
20275.44.26.7
20285.54.26.8
20295.64.36.8

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
Yolla Bolly3720241973
Tres Pinos 23520112005
Ono3220121984
Adelaida3220241970
Coyote3220241973
Sisquoc3020141991
Lake Berryessa2620242023
Glenn2520231978
Gold Hill2420241971
Ingalls2320011973
Macdoel2320191972
Mark West2320241972
Moraga2120241972
Tres Pinos1920021968
South Lake1720062006
Tracy 21720232010
Parkfield1620241968
Point Reyes1620231970
Hollister 21620242012
Blythe1520031973
Collegeville 21520142013
Crescent Cty1420241972
Pennington1420241971

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 2026-05-22.