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Species · Pennsylvania · BBS 2026 Release · 1966–2025

Prairie Warbler Population Trend in Pennsylvania

All statesForest birds

Prairie Warbler in Pennsylvania has edged down: down 13% on the route-weighted index since 1968.

-13%Since 1968TrendPercent 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 →
89Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Prairie Warbler 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 →

No notable trend signals for Prairie Warbler in Pennsylvania. See the full index history below.

Prairie Warbler Population Forecast in Pennsylvania

If the recent trend holds, Prairie Warbler in Pennsylvania is projected to fall about 16% by 2030 — from 0.22 in 2025 to a central estimate of 0.18 (95% range 0.00–0.44). A 5-year backtest shows a typical error of ±34.4%, with 100% of held-out values landing inside the 95% band.

-16%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 →
0.18Projected 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 →
0.00–0.4495% 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 →
±34.4%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, Prairie Warbler in Pennsylvania is projected to fall about 16% by 2030 — from 0.22 in 2025 to a central estimate of 0.18 (95% range 0.00–0.44). A 5-year backtest shows a typical error of ±34.4%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20260.200.000.46
20270.200.000.46
20280.190.000.45
20290.190.000.45
20300.180.000.44

Prairie Warbler Survey Routes in Pennsylvania

Routes recording Prairie Warbler 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 →
Mars519951991
Rush320251984
Berwick320251995
Little Marsh220151997
English Ctr219891988
Greentown220231995
Poyntelle220251974
Plesant Grov220122012
Munson220251980
Ryde220041992
Drehersville219991985
Normalville219701966
Big Flat219781976
Landisburg219981978
Clover119951995
Harmonsburg119891989
Teepleville119941977
Sigel120241981
Lynch120191971
N Washington120251970
N Pine Grove120021981
Pottersdale119881973
Ramsey120121970
Rosecrans120071970
Cherry Sprs120122012

Prairie Warbler Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamainemarylandmassachusettsmichiganmississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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