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

Alder Flycatcher In Atlantic Northern Forest

All regionsAtlantic Northern ForestAerial insectivores

Alder Flycatcher in Atlantic Northern Forest has risen sharply: up 55% on the route-weighted index since 1968.

+55%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 →
153Routes 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 →

Alder Flycatcher has risen sharply in Atlantic Northern Forest: up 55% on the route-weighted index since 1968.

Alder Flycatcher In Atlantic Northern Forest Population Forecast

If the recent trend holds, Alder Flycatcher in Atlantic Northern Forest is projected to rise about 16% by 2029 — from 4.2 in 2024 to a central estimate of 4.8 (95% range 3.4–6.2). A 5-year backtest shows a typical error of ±14.2%, with 100% of held-out values landing inside the 95% band.

+16%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 →
4.8Projected 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 →
3.4–6.295% 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 →
±14.2%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, Alder Flycatcher in Atlantic Northern Forest is projected to rise about 16% by 2029 — from 4.2 in 2024 to a central estimate of 4.8 (95% range 3.4–6.2). A 5-year backtest shows a typical error of ±14.2%, 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 →
20254.73.36.1
20264.73.36.1
20274.73.36.2
20284.83.46.2
20294.83.46.2

Routes In Atlantic Northern Forest

Routes recording Alder 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 →
St DavidMAINE212005
HarmonyMAINE172024
BentonMAINE151980
LudlowMAINE151998
Ft FairfieldMAINE152005
St Regis FlsNEW-YORK152017
Baker LakeMAINE132009
StrattonVERMONT132024
HardwickVERMONT132024
DebloisMAINE122007
StratfordNEW-HAMPSHIRE122024
DegrasseNEW-YORK112024
StoweVERMONT112024
CooperMAINE102021
NorthfieldMAINE101981
WashburnMAINE102005
WanakenaNEW-YORK102024
LandgroveVERMONT102024
MiddlesexVERMONT102024
Newbury 2VERMONT102023
WarrenMAINE91990
Forest StaMAINE92000
Dixvil NotchNEW-HAMPSHIRE92017
HancockMAINE82024
BoundaryMAINE82016

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