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

Black Vulture Population Trend in Arizona

All statesBirds of prey

Black Vulture in Arizona has fallen sharply: down 53% on the route-weighted index since 1977.

-53%Since 1977TrendPercent 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 →
12Routes 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 →
33YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black Vulture Trends in ArizonaNotable 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 declinecomputed 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 →

Black Vulture has fallen sharply in Arizona: down 53% on the route-weighted index since 1977.

Black Vulture Population Forecast in Arizona

If the recent trend holds, Black Vulture in Arizona is projected to fall about 25% by 2030 — from 0.51 in 2025 to a central estimate of 0.38 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±64.4%, with 80% of held-out values landing inside the 95% band.

-25%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 →
0.38Projected 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 →
0.00–1.495% 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 →
±64.4%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, Black Vulture in Arizona is projected to fall about 25% by 2030 — from 0.51 in 2025 to a central estimate of 0.38 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±64.4%, with 80% of held-out values landing inside the 95% band.19752030
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 →
20260.390.001.4
20270.390.001.4
20280.390.001.4
20290.380.001.4
20300.380.001.4

Black Vulture Survey Routes in Arizona

Routes recording Black Vulture in Arizona.
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 →
Casa Grande8120222011
Amado1820251993
Palo Verde 2420232017
Lukeville419791975
Red Rock320142000
Red Rock 2320242015
Patagonia220251995
Organ Pipe220231990
Cactus Forest120231997
Ajo120011999
Pomerene120252025
Peña Blanca120001997

Black Vulture Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamarylandmassachusettsmississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniasouth-carolinatennesseetexasvermontvirginiawest-virginia

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