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Species · Pennsylvania · BBS 2026 Release · 1966–2025

Scarlet Tanager Population Trend in Pennsylvania

All statesForest birds

Scarlet Tanager in Pennsylvania has risen sharply: up 67% on the route-weighted index since 1968.

+67%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 →
134Routes 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 Scarlet Tanager 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 →

Scarlet Tanager has risen sharply in Pennsylvania: up 67% on the route-weighted index since 1968.

Scarlet Tanager Population Forecast in Pennsylvania

If the recent trend holds, Scarlet Tanager in Pennsylvania is projected to rise about 30% by 2030 — from 6.7 in 2025 to a central estimate of 8.7 (95% range 6.1–11). A 5-year backtest shows a typical error of ±36.8%, with 20% of held-out values landing inside the 95% band.

+30%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 →
8.7Projected 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 →
6.1–1195% 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 →
±36.8%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, Scarlet Tanager in Pennsylvania is projected to rise about 30% by 2030 — from 6.7 in 2025 to a central estimate of 8.7 (95% range 6.1–11). A 5-year backtest shows a typical error of ±36.8%, with 20% 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 →
20268.65.911
20278.66.011
20288.76.011
20298.76.111
20308.76.111

Scarlet Tanager Survey Routes in Pennsylvania

Routes recording Scarlet Tanager 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.4920251993
Stoneybreak2320251992
Laurel Hill2120251978
Duboistown2020241987
N Pine Grove1820251969
Mawr Glen1820251966
Ryde1820051968
Mill Run1820251978
Marsh Hill1620251983
Rothrock Sf1620191992
Ltl Pine Cr1520251990
Waller1420251971
Broad Mtn.1420251993
Greentown1320241969
Geeseytown1220251987
Warrens Mill1220251971
Landisburg1220251978
Rush1120251970
Naginey1120251973
Sigel1020251981
Roulette1020211970
Honesdale1020251972
Canadensis1020251969
Rector1019771966
St College1020251969

Scarlet Tanager Population Trend in Other States

alabamaarkansasconnecticutdelawaregeorgiaillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomarhode-islandsouth-carolinatennesseevermontvirginiawest-virginiawisconsin

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