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

Black Vulture Population Trend in Arizona

All statesGeneralists

Black Vulture in Arizona has increased: up 46% on the route-weighted index since 1977.

+46%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 →
11Routes 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 →
32YearsYears 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 →

No notable trend signals for Black Vulture in Arizona. See the full index history below.

Black Vulture Population Forecast in Arizona

If the recent trend holds, Black Vulture in Arizona is projected to rise about 329% by 2029 — from 0.09 in 2024 to a central estimate of 0.37 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±52.2%, with 80% of held-out values landing inside the 95% band.

+329%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 →
0.37Projected 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 →
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 →
±52.2%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 rise about 329% by 2029 — from 0.09 in 2024 to a central estimate of 0.37 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±52.2%, with 80% of held-out values landing inside the 95% band.19752029
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 →
20250.380.001.4
20260.370.001.4
20270.370.001.4
20280.370.001.4
20290.370.001.4

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
Patagonia620231995
Palo Verde 2420232017
Lukeville419791975
Red Rock320142000
Red Rock 2320242015
Organ Pipe220231990
Amado120231993
Ajo120011999
Cactus Forest120231997
Peña Blanca120001997

Black Vulture Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamarylandmassachusettsmississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniasouth-carolinatennesseetexasvermontvirginiawest-virginia

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