BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Hermit Thrush In Great Basin

All regionsGreat BasinForest birds

Hermit Thrush in Great Basin has edged down: down 11% on the route-weighted index since 1970.

-11%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 →
84Routes 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 Hermit Thrush in Great Basin. See the full index history below.

Hermit Thrush In Great Basin Population Forecast

If the recent trend holds, Hermit Thrush in Great Basin is projected to stay roughly flat through 2029, near 2.3 (95% range 1.4–3.1). A 5-year backtest shows a typical error of ±9.8%, with 100% of held-out values landing inside the 95% band.

-0%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 →
2.3Projected 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 →
1.4–3.195% 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 →
±9.8%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 Great Basin is projected to stay roughly flat through 2029, near 2.3 (95% range 1.4–3.1). A 5-year backtest shows a typical error of ±9.8%, 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 →
20252.21.43.1
20262.21.43.1
20272.21.43.1
20282.31.43.1
20292.31.43.1

Routes In Great Basin

Routes recording Hermit Thrush in Great Basin.
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 →
Blewett PassWASHINGTON692024
PauninaOREGON352024
Bald Mtn.OREGON342024
E. Mt. AdamsWASHINGTON272024
RonaldWASHINGTON232024
Medicine Mtn.CALIFORNIA202021
Mt HoodOREGON202024
GlacierWASHINGTON142024
Davis LakeOREGON132024
RimrockWASHINGTON132024
BartleCALIFORNIA112021
TionestaCALIFORNIA112021
Magic MtnIDAHO102024
Barnes ValOREGON91987
SistersOREGON92024
ZumwaltOREGON81996
IndexWASHINGTON81997
No CascadesWASHINGTON82019
TwispWASHINGTON72015
LeavenworthWASHINGTON72024
Wizard FallsOREGON62024
ChinchaloOREGON62024
Walker CanNEVADA51968
LakeviewOREGON52024
HyrumUTAH51977

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