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

Warbling Vireo In Atlantic Northern Forest

All regionsAtlantic Northern ForestForest birds

Warbling Vireo in Atlantic Northern Forest has surged: up 93% on the route-weighted index since 1968.

+93%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 →
139Routes 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 →
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 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 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 →

Warbling Vireo has surged in Atlantic Northern Forest: up 93% on the route-weighted index since 1968.

Warbling Vireo In Atlantic Northern Forest Population Forecast

If the recent trend holds, Warbling Vireo in Atlantic Northern Forest is projected to stay roughly flat through 2029, near 1.4 (95% range 0.76–2.1). A 5-year backtest shows a typical error of ±9.5%, with 100% of held-out values landing inside the 95% band.

+8%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 →
1.4Projected 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 →
0.76–2.195% 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 →
±9.5%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, Warbling Vireo in Atlantic Northern Forest is projected to stay roughly flat through 2029, near 1.4 (95% range 0.76–2.1). A 5-year backtest shows a typical error of ±9.5%, 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 →
20251.40.742.1
20261.40.752.1
20271.40.752.1
20281.40.762.1
20291.40.762.1

Routes In Atlantic Northern Forest

Routes recording Warbling Vireo 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 →
FletcherVERMONT122024
Otisfield GrMAINE112015
Seboomook LkMAINE112010
TurnerMAINE82010
W RutlandVERMONT62024
StacyvilleMAINE52023
MontereyMASSACHUSETTS52024
MarlowNEW-HAMPSHIRE52024
S WallingfrdVERMONT52022
WatervilleVERMONT51980
HarmonyMAINE42024
Carrying PlMAINE42015
MedwayMAINE42018
ChesterfieldMASSACHUSETTS42024
ConcordNEW-HAMPSHIRE42024
Dixvil NotchNEW-HAMPSHIRE42008
GaysvilleVERMONT42021
HartfordMAINE32024
ManchesterMAINE31995
East TroyMAINE31996
WarrenMAINE31990
NorthfieldMAINE31978
WashburnMAINE32005
Ft FairfieldMAINE32005
RomeMAINE32024

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