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Species · BCR 14 · BBS 2025 Release · 1966–2024

Wilson's Warbler In Atlantic Northern Forest

All regionsAtlantic Northern ForestForest birds

Wilson's Warbler in Atlantic Northern Forest has collapsed: down 91% on the route-weighted index since 1968.

-91%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 →
57Routes 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 →
50YearsYears 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 →

long arc declinecomputed 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 →

Wilson's Warbler has collapsed in Atlantic Northern Forest: down 91% on the route-weighted index since 1968.

Wilson's Warbler In Atlantic Northern Forest Population Forecast

If the recent trend holds, Wilson's Warbler in Atlantic Northern Forest is projected to stay roughly flat through 2027, near 0.01 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±79.5%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.01Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0995% 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 →
±79.5%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 Atlantic Northern Forest is projected to stay roughly flat through 2027, near 0.01 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±79.5%, with 100% of held-out values landing inside the 95% band.19662027
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 →
20230.010.000.10
20240.010.000.10
20250.010.000.10
20260.010.000.10
20270.010.000.09

Routes In Atlantic Northern Forest

Routes recording Wilson's Warbler in Atlantic Northern Forest.
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 →
Mt ChocoruaNEW-HAMPSHIRE61975
FranconiaNEW-HAMPSHIRE61975
Jefferson HlNEW-HAMPSHIRE51966
LudlowMAINE31983
AuroraMAINE22004
NorthfieldMAINE21981
HudsonMAINE21988
Forest StaMAINE22000
Pillsbury PdMAINE21968
Ft FairfieldMAINE21993
NesowadnehunMAINE22009
TopsfieldMAINE21992
Heron LakeMAINE22003
MilanNEW-HAMPSHIRE22015
Wilson MillsMAINE11993
BethelMAINE11989
ReedsMAINE11999
South ArmMAINE11998
Otisfield GrMAINE12001
HartfordMAINE11977
ManchesterMAINE11981
WarrenMAINE11974
FreedomMAINE11974
HermonMAINE11984
HancockMAINE12000

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