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Species · BCR 14 · BBS 2026 Release · 1966–2025

Alder Flycatcher In Atlantic Northern Forest

All regionsAtlantic Northern ForestAerial insectivores

Alder Flycatcher in Atlantic Northern Forest has risen sharply: up 60% on the route-weighted index since 1968.

+60%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 →
59YearsYears 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 60% 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 18% by 2030 — from 4.1 in 2025 to a central estimate of 4.8 (95% range 3.4–6.2). A 5-year backtest shows a typical error of ±15.2%, with 100% of held-out values landing inside the 95% band.

+18%Change by 2030TrendPercent 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 2030 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 →
±15.2%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 18% by 2030 — from 4.1 in 2025 to a central estimate of 4.8 (95% range 3.4–6.2). A 5-year backtest shows a typical error of ±15.2%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20264.73.36.1
20274.73.36.1
20284.83.36.2
20294.83.46.2
20304.83.46.2

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 →
East TroyMAINE212021
St DavidMAINE212005
HarmonyMAINE162025
Dixville Notch 2NEW-HAMPSHIRE162025
BentonMAINE151980
LudlowMAINE151998
Ft FairfieldMAINE152005
St Regis FlsNEW-YORK152017
Baker LakeMAINE132009
HardwickVERMONT132024
HermonMAINE122021
DebloisMAINE122007
StrattonVERMONT122025
MiddlesexVERMONT122025
StoweVERMONT112024
CooperMAINE102021
NorthfieldMAINE101981
WashburnMAINE102005
MontereyMASSACHUSETTS102025
GreensboroVERMONT102025
Newbury 2VERMONT102023
WarrenMAINE91990
Forest StaMAINE92000
Dixvil NotchNEW-HAMPSHIRE92017
East HavenVERMONT92025

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.