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

Willow Flycatcher In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionAerial insectivores

Willow Flycatcher in Boreal Hardwood Transition has fallen sharply: down 68% on the route-weighted index since 1975.

-68%Since 1975TrendPercent 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 →
43Routes 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 →
47YearsYears 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 declinecomputed 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 fallen sharply in Boreal Hardwood Transition: down 68% on the route-weighted index since 1975.

Willow Flycatcher In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Willow Flycatcher in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±30.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.03Projected 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 →
0.00–0.1595% 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 →
±30.1%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 Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±30.1%, with 100% of held-out values landing inside the 95% band.19732029
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 →
20250.030.000.15
20260.030.000.15
20270.030.000.15
20280.030.000.15
20290.030.000.15

Routes In Boreal Hardwood Transition

Routes recording Willow 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 →
Skegemog PtMICHIGAN41987
MareniscoMICHIGAN32012
FredericMICHIGAN32001
CathroMICHIGAN31989
Seney NwrMICHIGAN31994
Pleasant ValMICHIGAN21986
Walloon LakeMICHIGAN21985
DebsMINNESOTA22017
LudeMINNESOTA21985
ChaffeyWISCONSIN22016
WilsonMICHIGAN11990
CunardMICHIGAN12019
Bear LakeMICHIGAN12023
GilchristMICHIGAN12005
Lake CityMICHIGAN12001
RiggsvilleMICHIGAN12018
SkeelsMICHIGAN11989
Red OakMICHIGAN11985
OberlinMICHIGAN12024
Sand LakeMICHIGAN12024
Hubbard LakeMICHIGAN11995
HerronMICHIGAN12016
MayfieldMICHIGAN12017
Mille LacsMINNESOTA12016
BackusMINNESOTA11994

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