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Species · Pennsylvania · BBS 2025 Release · 1966–2024

Pine Warbler Population Trend in Pennsylvania

All statesForest birds

Pine Warbler in Pennsylvania has surged: up 904% on the route-weighted index since 1970.

+904%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 →
68Routes 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 Pine 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 →

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 →

Pine Warbler has surged in Pennsylvania: up 904% on the route-weighted index since 1970.

Pine Warbler Population Forecast in Pennsylvania

If the recent trend holds, Pine Warbler in Pennsylvania is projected to fall about 23% by 2029 — from 0.45 in 2024 to a central estimate of 0.35 (95% range 0.24–0.45). A 5-year backtest shows a typical error of ±20.5%, with 60% of held-out values landing inside the 95% band.

-23%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 →
0.35Projected 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 →
0.24–0.4595% 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 →
±20.5%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, Pine Warbler in Pennsylvania is projected to fall about 23% by 2029 — from 0.45 in 2024 to a central estimate of 0.35 (95% range 0.24–0.45). A 5-year backtest shows a typical error of ±20.5%, with 60% of held-out values landing inside the 95% band.19672029
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 →
20250.320.220.43
20260.330.230.43
20270.340.230.44
20280.340.240.45
20290.350.240.45

Pine Warbler Survey Routes in Pennsylvania

Routes recording Pine 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 →
Pocono Summit520241967
Clear Spring520241989
Canadensis420241992
Stoneybreak420241992
Wild Creek320231989
Hop Bottom320242019
Virginia319741972
Sproul Sf-A320232005
Teepleville220222004
Sigel219991999
Pocono Summit 2220072007
Rosecrans220221977
Rush220212021
Waller220241978
Millville220181998
Honesdale220241993
Bendersville219921992
St College220241969
Jacobus220221992
Normalville219731972
West Grove219921992
Sproul Sf-B220222016
Ltl Pine Cr220241991
Espyville120222001
Ellenton119971988

Pine Warbler Population Trend in Other States

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

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