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Species · Pennsylvania · BBS 2026 Release · 1966–2025

Canada Warbler Population Trend in Pennsylvania

All statesForest birds

Canada Warbler in Pennsylvania has risen sharply: up 66% on the route-weighted index since 1968.

+66%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 →
60Routes 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 Canada 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 →

Canada Warbler has risen sharply in Pennsylvania: up 66% on the route-weighted index since 1968.

Canada Warbler Population Forecast in Pennsylvania

If the recent trend holds, Canada Warbler in Pennsylvania is projected to stay roughly flat through 2030, near 0.30 (95% range 0.16–0.45). A 5-year backtest shows a typical error of ±20.9%, with 100% of held-out values landing inside the 95% band.

-6%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 →
0.30Projected 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 →
0.16–0.4595% 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 →
±20.9%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, Canada Warbler in Pennsylvania is projected to stay roughly flat through 2030, near 0.30 (95% range 0.16–0.45). A 5-year backtest shows a typical error of ±20.9%, 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 →
20260.290.150.44
20270.300.150.44
20280.300.160.44
20290.300.160.44
20300.300.160.45

Canada Warbler Survey Routes in Pennsylvania

Routes recording Canada 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 →
Marsh Hill720251983
Sproul Sf-A620252002
Laurel Hill520251979
Starlight419921978
Duboistown420241987
Poyntelle320241973
N Washington219781978
N Pine Grove220221970
Starlight 2220002000
Rothrock Sf220181992
Roulette220111972
Little Marsh219941994
Rush220251971
Ralston219721972
Hop Bottom220061967
Munson220231987
Broad Mtn.220251994
New Ringgold219661966
Garrett220251991
Ltl Pine Cr220241992
Harmonsburg119961994
Ellenton120241984
Whig Hill120011998
Akeley119711967
Teepleville119881974

Canada Warbler Population Trend in Other States

connecticutgeorgiaindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiorhode-islandtennesseevermontvirginiawest-virginiawisconsin

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