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

Willow Flycatcher In Atlantic Northern Forest

All regionsAtlantic Northern ForestAerial insectivores

Willow Flycatcher in Atlantic Northern Forest has surged: up 432% on the route-weighted index since 1968.

+432%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 →
89Routes 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 →
57YearsYears 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 →

Willow Flycatcher has surged in Atlantic Northern Forest: up 431% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Willow Flycatcher in Atlantic Northern Forest is projected to stay roughly flat through 2029, near 0.24 (95% range 0.07–0.40). A 5-year backtest shows a typical error of ±23.3%, with 100% of held-out values landing inside the 95% band.

-2%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 →
0.24Projected 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 →
0.07–0.4095% 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 →
±23.3%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, Willow Flycatcher in Atlantic Northern Forest is projected to stay roughly flat through 2029, near 0.24 (95% range 0.07–0.40). A 5-year backtest shows a typical error of ±23.3%, 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 →
20250.230.060.40
20260.230.070.40
20270.230.070.40
20280.230.070.40
20290.240.070.40

Routes In Atlantic Northern Forest

Routes recording Willow Flycatcher 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 →
Northfld FlsVERMONT101997
GabrielsNEW-YORK41998
DannemoraNEW-YORK41995
W RutlandVERMONT42024
New HartfordCONNECTICUT31987
ChesterfieldMASSACHUSETTS32021
East CalaisVERMONT31983
Wilson MillsMAINE21990
Otisfield GrMAINE22000
CharlestonMAINE22014
WytopitlockMAINE21996
BenedictaMAINE21993
WilmotNEW-HAMPSHIRE22019
Jefferson HlNEW-HAMPSHIRE22024
StratfordNEW-HAMPSHIRE22002
PetersburgNEW-YORK22011
S WallingfrdVERMONT22021
FletcherVERMONT22024
New HartfordCONNECTICUT11994
WestbrookMAINE12014
BiddefordMAINE12008
TurnerMAINE12010
GreenwoodMAINE12021
ReedsMAINE12022
HartfordMAINE12019

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