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Species · Pennsylvania · BBS 2026 Release · 1966–2025

Red-eyed Vireo Population Trend in Pennsylvania

All statesForest birds

Red-eyed Vireo in Pennsylvania has surged: up 204% on the route-weighted index since 1968.

+204%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 →
136Routes 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 Red-eyed Vireo 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 →

Red-eyed Vireo has surged in Pennsylvania: up 204% on the route-weighted index since 1968.

Red-eyed Vireo Population Forecast in Pennsylvania

If the recent trend holds, Red-eyed Vireo in Pennsylvania is projected to rise about 16% by 2030 — from 40 in 2025 to a central estimate of 46 (95% range 41–51). A 5-year backtest shows a typical error of ±4.6%, 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 →
46Projected 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 →
41–5195% 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 →
±4.6%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, Red-eyed Vireo in Pennsylvania is projected to rise about 16% by 2030 — from 40 in 2025 to a central estimate of 46 (95% range 41–51). A 5-year backtest shows a typical error of ±4.6%, 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 →
2026443949
2027454050
2028454050
2029464151
2030464151

Red-eyed Vireo Survey Routes in Pennsylvania

Routes recording Red-eyed Vireo 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 →
Tussey Mtn.11820251993
Ellenton10520251982
Mill Run10220251978
Odin9820251973
Mawr Glen9520251966
Munson9420251979
Canadensis9220251969
Marsh Hill9120251983
Wild Creek8520251988
Greentown8320241969
Sigel8120251981
Duboistown7820241987
Stoneybreak7520251992
N Pine Grove7120251969
N Washington7020251967
Laurel Hill6820251978
Patton6420241970
Ansonia6420252002
Waller6320251971
Margaret6320251969
Rothrock Sf6320191992
Broad Mtn.6320251993
Virginia6220251969
Geeseytown6220251987
Pocono Summit6020251966

Red-eyed Vireo Population Trend in Other States

alabamaalaskaarkansascoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonrhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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