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Species · Pennsylvania · BBS 2026 Release · 1966–2025

Blue Jay Population Trend in Pennsylvania

All statesForest birds

Blue Jay in Pennsylvania has increased: up 35% on the route-weighted index since 1968.

+35%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 →
137Routes 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 Blue Jay 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 Blue Jay in Pennsylvania. See the full index history below.

Blue Jay Population Forecast in Pennsylvania

If the recent trend holds, Blue Jay in Pennsylvania is projected to rise about 15% by 2030 — from 10 in 2025 to a central estimate of 12 (95% range 9.8–13). A 5-year backtest shows a typical error of ±9.6%, with 100% of held-out values landing inside the 95% band.

+15%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 →
12Projected 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 →
9.8–1395% 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 →
±9.6%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, Blue Jay in Pennsylvania is projected to rise about 15% by 2030 — from 10 in 2025 to a central estimate of 12 (95% range 9.8–13). A 5-year backtest shows a typical error of ±9.6%, 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 →
2026119.613
2027119.613
2028119.713
2029129.713
2030129.813

Blue Jay Survey Routes in Pennsylvania

Routes recording Blue Jay 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 →
Collegeville4020241971
Wild Creek3820251988
Canadensis3220251969
Ryde2920051968
Drehersville 22820252000
Middletown2620251973
Mount Joy2620251978
Jacobus2620251986
Scheafferstn2520011966
Brunnerville 22320252010
Roulette2220211970
Doe Run2220251969
Schwenksvill2220241988
Portersville1919881973
Duvall1920211974
Plesant Grov1920241967
Little Marsh1820241967
Quakertown1819891970
Gatchelville1819901972
West Grove1719961966
Shrewsbury1720231991
Sigel1620251981
Poyntelle1620251969
Pottstown1619871966
N Pine Grove1520251969

Blue Jay Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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