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

Hermit Thrush In Northern Rockies

All regionsNorthern RockiesForest birds

Hermit Thrush in Northern Rockies has surged: up 238% on the route-weighted index since 1970.

+238%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 →
125Routes 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 →

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 →

Hermit Thrush has surged in Northern Rockies: up 238% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Hermit Thrush in Northern Rockies is projected to stay roughly flat through 2029, near 3.4 (95% range 2.0–4.8). A 5-year backtest shows a typical error of ±10.1%, with 100% of held-out values landing inside the 95% band.

+9%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 →
3.4Projected 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 →
2.0–4.895% 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 →
±10.1%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, Hermit Thrush in Northern Rockies is projected to stay roughly flat through 2029, near 3.4 (95% range 2.0–4.8). A 5-year backtest shows a typical error of ±10.1%, 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 →
20253.31.94.7
20263.31.94.7
20273.31.94.7
20283.42.04.7
20293.42.04.8

Routes In Northern Rockies

Routes recording Hermit Thrush 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 →
BarnhouseOREGON392024
OchocoOREGON361982
CloverlandWASHINGTON322024
Black Mtn.OREGON302004
Bald MtnWYOMING282024
West ThumbWYOMING261982
Hash RockOREGON252024
Twin LakesWASHINGTON231993
Deep CreekIDAHO201985
DonnellyOREGON202006
AlturasIDAHO181987
Silver CreekOREGON162024
Threemile WaMONTANA152024
Horse CreekWYOMING152024
Donelly 2OREGON142024
Fiddler LkWYOMING142024
LogdellOREGON132024
Eagle CreekOREGON132022
Howard Mdws.OREGON122024
MonumentOREGON122024
DesolationOREGON122007
Cramer CreekMONTANA112019
Elevation MtMONTANA112024
FloraOREGON112023
GraniteOREGON112024

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