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

Canada Warbler Population Trend in Pennsylvania

All statesForest birds

Canada Warbler in Pennsylvania has increased: up 46% on the route-weighted index since 1968.

+46%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 →
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 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 →

No notable trend signals for Canada Warbler in Pennsylvania. See the full index history below.

Canada Warbler Population Forecast in Pennsylvania

If the recent trend holds, Canada Warbler in Pennsylvania is projected to rise about 16% by 2029 — from 0.26 in 2024 to a central estimate of 0.30 (95% range 0.15–0.44). A 5-year backtest shows a typical error of ±37.6%, with 100% of held-out values landing inside the 95% band.

+16%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 →
0.30Projected 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 →
0.15–0.4495% 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 →
±37.6%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, Canada Warbler in Pennsylvania is projected to rise about 16% by 2029 — from 0.26 in 2024 to a central estimate of 0.30 (95% range 0.15–0.44). A 5-year backtest shows a typical error of ±37.6%, 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 →
20250.290.150.43
20260.290.150.43
20270.290.150.44
20280.300.150.44
20290.300.150.44

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 Hill520241983
Starlight419921978
Broad Mtn.420241994
Duboistown420241987
Ansonia320232004
Poyntelle320241973
N Washington219781978
N Pine Grove220221970
Starlight 2220002000
Rothrock Sf220181992
Roulette220111972
Little Marsh219941994
Ralston219721972
Hop Bottom220061967
Munson220231987
New Ringgold219661966
Sproul Sf-A220242002
Ltl Pine Cr220241992
Harmonsburg119961994
Ellenton120241984
Whig Hill120011998
Akeley119711967
Teepleville119881974
Sigel120102002
Lynch119981969

Canada Warbler Population Trend in Other States

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

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