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

Red-eyed Vireo Population Trend in Pennsylvania

All statesForest birds

Red-eyed Vireo in Pennsylvania has surged: up 212% on the route-weighted index since 1968.

+212%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 →
58YearsYears 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 212% 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 13% by 2029 — from 41 in 2024 to a central estimate of 46 (95% range 41–51). A 5-year backtest shows a typical error of ±3.5%, with 100% of held-out values landing inside the 95% band.

+13%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 →
46Projected 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 →
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 →
±3.5%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, Red-eyed Vireo in Pennsylvania is projected to rise about 13% by 2029 — from 41 in 2024 to a central estimate of 46 (95% range 41–51). A 5-year backtest shows a typical error of ±3.5%, with 100% of held-out values landing inside the 95% band.19662029
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 →
2025443949
2026454050
2027454050
2028464151
2029464151

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.14320241993
Odin10720241973
Mill Run10420241978
Ellenton9820241982
Munson8820241979
Stoneybreak8720241992
Wild Creek8720241988
Mawr Glen8520241966
Greentown8320241969
Marsh Hill8220241983
Duboistown7820241987
St College7620241969
Laurel Hill7620241978
Susquehanna7420241971
Warrens Mill7420241971
Roulette 27420242022
N Pine Grove7120241969
Sigel6520241981
Pocono Summit6520241966
Canadensis6520241969
Margaret6420241969
Patton6420241970
Rothrock Sf6320191992
Geeseytown6220241987
Ramsey6120231968

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 2026-05-22.