BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Willow Flycatcher In Appalachian Mountains

All regionsAppalachian MountainsAerial insectivores

Willow Flycatcher in Appalachian Mountains has surged: up 82% on the route-weighted index since 1968.

+82%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 →
271Routes 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 →

Willow Flycatcher has surged in Appalachian Mountains: up 82% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Willow Flycatcher in Appalachian Mountains is projected to rise about 36% by 2029 — from 0.73 in 2024 to a central estimate of 0.99 (95% range 0.44–1.5). A 5-year backtest shows a typical error of ±58.7%, with 100% of held-out values landing inside the 95% band.

+36%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 →
0.99Projected 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 →
0.44–1.595% 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 →
±58.7%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 →
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 →
20250.980.431.5
20260.980.431.5
20270.990.431.5
20280.990.441.5
20290.990.441.5

Routes In Appalachian Mountains

Routes recording Willow Flycatcher in Appalachian Mountains.
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 →
StonecreekOHIO162024
OmegaOHIO112024
CumberlandOHIO92017
SmithfieldOHIO82024
RiftonNEW-YORK71986
JeffersonPENNSYLVANIA72024
PoyntellePENNSYLVANIA62024
BeaverPENNSYLVANIA62024
Plesant GrovPENNSYLVANIA62024
KaylorPENNSYLVANIA62024
DrehersvillePENNSYLVANIA61999
Drehersville 2PENNSYLVANIA62024
MarionVIRGINIA61982
HebronVIRGINIA62003
DrydenNEW-YORK52024
S Berne 2NEW-YORK52018
DresdenOHIO52024
WallerPENNSYLVANIA52024
QuakertownPENNSYLVANIA51989
Mt NeboMARYLAND41989
SwainNEW-YORK42007
CentervilleNEW-YORK42013
Coal RunOHIO41992
RoulettePENNSYLVANIA42016
MartinsburgPENNSYLVANIA42024

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