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Species · BCR 12 · BBS 2025 Release · 1966–2024

Philadelphia Vireo In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionForest birds

Philadelphia Vireo in Boreal Hardwood Transition has fallen sharply: down 56% on the route-weighted index since 1973.

-56%Since 1973TrendPercent 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 →
31Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Philadelphia Vireo in Boreal Hardwood Transition. See the full index history below.

Philadelphia Vireo In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Philadelphia Vireo in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±38.1%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.03Projected 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 →
0.00–0.0795% 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 →
±38.1%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, Philadelphia Vireo in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±38.1%, with 80% of held-out values landing inside the 95% band.19702029
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 →
20250.030.000.08
20260.030.000.08
20270.030.000.08
20280.030.000.08
20290.030.000.07

Routes In Boreal Hardwood Transition

Routes recording Philadelphia Vireo in Boreal Hardwood Transition.
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 →
OntonagonMICHIGAN42019
IshpemingMICHIGAN42019
Crystal FlsMICHIGAN31988
BerglandMICHIGAN22022
Imp LakeMICHIGAN22012
HovlandMINNESOTA21998
JordanMINNESOTA22012
HermanMICHIGAN12013
CunardMICHIGAN12016
Lake CityMICHIGAN12001
PickfordMICHIGAN12011
Hiawatha NfMICHIGAN11994
SidnawMICHIGAN12013
Cluster LakesMICHIGAN12007
CromwellMINNESOTA11979
Mille LacsMINNESOTA12010
LockportMINNESOTA12010
Hart LakeMINNESOTA12002
FloodwoodMINNESOTA11972
CohassetMINNESOTA11994
Crane LakeMINNESOTA12024
LudeMINNESOTA12013
McgregorMINNESOTA12004
Sawbill CampMINNESOTA12011
BigforkMINNESOTA11994

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