BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Willow Flycatcher In Northern Rockies

All regionsNorthern RockiesAerial insectivores

Willow Flycatcher in Northern Rockies has declined: down 41% on the route-weighted index since 1970.

-41%Since 1970TrendPercent 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 →
157Routes 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 →
56YearsYears 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 →

No notable trend signals for Willow Flycatcher in Northern Rockies. See the full index history below.

Forecast

If the recent trend holds, Willow Flycatcher in Northern Rockies is projected to stay roughly flat through 2029, near 2.0 (95% range 1.1–2.9). A 5-year backtest shows a typical error of ±11.6%, with 100% of held-out values landing inside the 95% band.

+1%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 →
2.0Projected 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 →
1.1–2.995% 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 →
±11.6%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 Northern Rockies is projected to stay roughly flat through 2029, near 2.0 (95% range 1.1–2.9). A 5-year backtest shows a typical error of ±11.6%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20252.01.12.9
20262.01.12.9
20272.01.12.9
20282.01.12.9
20292.01.12.9

Routes In Northern Rockies

Routes recording Willow Flycatcher in Northern Rockies.
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 →
ChestnutMONTANA422024
CabartonIDAHO242023
SulaMONTANA182024
NaplesIDAHO162024
PierceIDAHO152007
ClancyMONTANA152023
Libby DamMONTANA142024
WilsonWYOMING142024
WoodmanMONTANA122024
CascadeIDAHO111984
Deer ParkWASHINGTON102015
KalispellMONTANA92024
Fish CreekMONTANA92024
DonnellyOREGON91995
Cape HornIDAHO82024
Marble CreekIDAHO82023
Rochat DivdeIDAHO82023
ClintonMONTANA82024
NinemileMONTANA82024
BridgeportOREGON82022
Buckskin MtnWYOMING82021
Nezperce NfIDAHO71999
LimaMONTANA72024
East Glacier ParkMONTANA62024
Fort LoganMONTANA62024

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