BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Alder Flycatcher In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionAerial insectivores

Alder Flycatcher in Boreal Hardwood Transition has surged: up 125% on the route-weighted index since 1968.

+125%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 →
121Routes 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 surged in Boreal Hardwood Transition: up 125% on the route-weighted index since 1968.

Alder Flycatcher In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Alder Flycatcher in Boreal Hardwood Transition is projected to rise about 47% by 2029 — from 4.8 in 2024 to a central estimate of 7.1 (95% range 5.4–8.8). A 5-year backtest shows a typical error of ±21%, with 80% of held-out values landing inside the 95% band.

+47%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 →
7.1Projected 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 →
5.4–8.895% 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 →
±21%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 Boreal Hardwood Transition is projected to rise about 47% by 2029 — from 4.8 in 2024 to a central estimate of 7.1 (95% range 5.4–8.8). A 5-year backtest shows a typical error of ±21%, with 80% 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 →
20256.85.28.5
20266.95.28.6
20277.05.38.6
20287.05.48.7
20297.15.48.8

Routes In Boreal Hardwood Transition

Routes recording Alder Flycatcher in Boreal Hardwood Transition.
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 →
Sherry LakeMINNESOTA782022
PickfordMICHIGAN352024
CromwellMINNESOTA182024
MareniscoMICHIGAN172019
JordanMINNESOTA172023
ChisholmMINNESOTA172024
GilmanWISCONSIN142024
Weirgor SpringsWISCONSIN142024
GlendaleMINNESOTA132024
Brocky LakeMICHIGAN122024
FloodwoodMINNESOTA122024
LudeMINNESOTA122023
MahtowaMINNESOTA112023
HermanMICHIGAN102022
Hart LakeMINNESOTA102024
WaskishMINNESOTA102024
GreenbushMINNESOTA102024
Amnicon FallsWISCONSIN102024
GilchristMICHIGAN92021
RacoMICHIGAN92024
Scott'S MarshMICHIGAN92010
McgregorMINNESOTA92024
BigforkMINNESOTA92024
Nett LakeMINNESOTA92024
Iron RiverWISCONSIN92024

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