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

Least Flycatcher In Northern Rockies

All regionsNorthern RockiesAerial insectivores

Least Flycatcher in Northern Rockies has surged: up 590% on the route-weighted index since 1972.

+590%Since 1972TrendPercent 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 →
78Routes 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 →
53YearsYears 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 →

Least Flycatcher has surged in Northern Rockies: up 590% on the route-weighted index since 1972.

Least Flycatcher In Northern Rockies Population Forecast

If the recent trend holds, Least Flycatcher in Northern Rockies is projected to rise about 20% by 2029 — from 0.29 in 2024 to a central estimate of 0.35 (95% range 0.15–0.54). A 5-year backtest shows a typical error of ±10.2%, with 100% of held-out values landing inside the 95% band.

+20%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 →
0.35Projected 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 →
0.15–0.5495% 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 →
±10.2%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, Least Flycatcher in Northern Rockies is projected to rise about 20% by 2029 — from 0.29 in 2024 to a central estimate of 0.35 (95% range 0.15–0.54). A 5-year backtest shows a typical error of ±10.2%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.330.130.53
20260.330.140.53
20270.340.140.53
20280.340.150.54
20290.350.150.54

Routes In Northern Rockies

Routes recording Least 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 →
Libby DamMONTANA392015
Yellow PineIDAHO71993
NaplesIDAHO62024
Fish CreekMONTANA42000
Painted RockMONTANA42010
Clyde ParkMONTANA42024
Pablo Res.MONTANA32015
St. Mary 2MONTANA32024
Wolf CreekMONTANA32022
Church HillMONTANA32024
GreenoughMONTANA32002
Hunter PeakWYOMING32010
MeeteetseWYOMING32024
HarmonyWYOMING32022
LayCOLORADO22024
Lolo PassIDAHO22019
BurgdorfIDAHO21992
FeathervilleIDAHO21996
KalispellMONTANA22018
St RegisMONTANA22009
ArleeMONTANA22022
AugustaMONTANA22024
Red RockMONTANA22008
NinemileMONTANA22008
Wise RiverMONTANA22008

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