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

Wilson's Warbler In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionForest birds

Wilson's Warbler in Boreal Hardwood Transition has edged down: down 20% on the route-weighted index since 1986.

-20%Since 1986TrendPercent 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 →
20Routes 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 →
37YearsYears 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 Wilson's Warbler in Boreal Hardwood Transition. See the full index history below.

Wilson's Warbler In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Wilson's Warbler in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.05 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±445.5%, with 100% 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 →
0.05Projected 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 →
0.00–0.1295% 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 →
±445.5%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, Wilson's Warbler in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.05 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±445.5%, with 100% of held-out values landing inside the 95% band.19802029
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 →
20250.050.000.12
20260.050.000.12
20270.050.000.12
20280.050.000.12
20290.050.000.12

Routes In Boreal Hardwood Transition

Routes recording Wilson's Warbler 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 →
GreenbushMINNESOTA92013
HovlandMINNESOTA41991
Scott'S MarshMICHIGAN22009
LudeMINNESOTA22010
Nett LakeMINNESOTA22014
BootjackMICHIGAN11998
MuskallongeMICHIGAN12011
GilchristMICHIGAN12015
RacoMICHIGAN12001
EnsignMICHIGAN12009
LockportMINNESOTA12009
Sawbill LndgMINNESOTA12005
WaskishMINNESOTA11981
McgregorMINNESOTA12023
Sawbill CampMINNESOTA12018
JordanMINNESOTA12022
GlendaleMINNESOTA12022
Red LakeMINNESOTA12024
WarroadMINNESOTA12012
Iron RiverWISCONSIN12008

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