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

Black Vulture Population Trend in Pennsylvania

All statesGeneralists

Black Vulture in Pennsylvania has surged: up 490% on the route-weighted index since 1979.

+490%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 →
49Routes 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 →
42YearsYears 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 PennsylvaniaNotable 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 →

Black Vulture has surged in Pennsylvania: up 490% on the route-weighted index since 1979.

Black Vulture Population Forecast in Pennsylvania

If the recent trend holds, Black Vulture in Pennsylvania is projected to rise about 100% by 2029 — from 0.20 in 2024 to a central estimate of 0.40 (95% range 0.00–0.81). A 5-year backtest shows a typical error of ±113.5%, with 100% of held-out values landing inside the 95% band.

+100%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 →
0.40Projected 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 →
0.00–0.8195% 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 →
±113.5%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 Pennsylvania is projected to rise about 100% by 2029 — from 0.20 in 2024 to a central estimate of 0.40 (95% range 0.00–0.81). A 5-year backtest shows a typical error of ±113.5%, with 100% of held-out values landing inside the 95% band.19702029
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 →
20250.370.000.77
20260.380.000.78
20270.390.000.79
20280.400.000.80
20290.400.000.81

Black Vulture Survey Routes in Pennsylvania

Routes recording Black Vulture in Pennsylvania.
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 →
Mt Gretna 23720172006
Landisburg1020171981
Drehersville 2720212006
Doe Run620211979
Berwick420222022
Doylesburg420232015
Ryde420032003
Peru Mills420171989
Jacobus420242010
Aspers419881988
Lovelton320222022
Honesdale320232023
Schaefferstown 2320242008
Shrewsbury320211997
Middletown320241992
Leola220232014
Rosecrans220132013
Mount Joy220241988
Brunnerville 2220212016
Williamsburg220132008
St College220171993
Bendersville220231997
Chatham220241998
New Ringgold220152015
Clearfield220212012

Black Vulture Population Trend in Other States

alabamaarizonaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamarylandmassachusettsmississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomasouth-carolinatennesseetexasvermontvirginiawest-virginia

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