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Species · Pennsylvania · BBS 2025 Release · 1966–2024

Yellow-throated Warbler Population Trend in Pennsylvania

All statesForest birds

Yellow-throated Warbler in Pennsylvania has risen sharply: up 64% on the route-weighted index since 1971.

+64%Since 1971TrendPercent 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 →
23Routes 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 →
49YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-throated 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 →

Yellow-throated Warbler has risen sharply in Pennsylvania: up 64% on the route-weighted index since 1971.

Yellow-throated Warbler Population Forecast in Pennsylvania

If the recent trend holds, Yellow-throated Warbler in Pennsylvania is projected to fall about 21% by 2029 — from 0.07 in 2024 to a central estimate of 0.05 (95% range 0.01–0.09). A 5-year backtest shows a typical error of ±57.1%, with 100% of held-out values landing inside the 95% band.

-21%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 →
0.05Projected 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 →
0.01–0.0995% 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 →
±57.1%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, Yellow-throated Warbler in Pennsylvania is projected to fall about 21% by 2029 — from 0.07 in 2024 to a central estimate of 0.05 (95% range 0.01–0.09). A 5-year backtest shows a typical error of ±57.1%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.050.010.09
20260.050.010.09
20270.050.010.09
20280.050.010.09
20290.050.010.09

Yellow-throated Warbler Survey Routes in Pennsylvania

Routes recording Yellow-throated 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 →
N Washington419701970
Shelocta320241992
Jefferson220241978
Lynch119701970
Rasselas120042004
English Ctr119891988
Cherry Sprs120082005
Mawr Glen120152013
Waller120142014
Canadensis120152015
Beaver120232022
Plesant Grov120172017
Parkwood120231992
Kittanning120222022
Sardis119691969
Margaret120161988
Virginia119711970
Mill Run120041990
Geeseytown120242024
Waterstreet120182015
St College119881988
Pine Gr Mill120222019
Ltl Pine Cr120011990

Yellow-throated Warbler Population Trend in Other States

alabamaarkansascaliforniadelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamarylandmichiganmississippimissourinew-jerseynorth-carolinaohiooklahomaoregonsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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