BirdAnalyst
Species · BCR 15 · BBS 2026 Release · 1966–2025

Hermit Thrush In Sierra Nevada

All regionsSierra NevadaForest birds

Hermit Thrush in Sierra Nevada has declined: down 49% on the route-weighted index since 1972.

-49%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 →
36Routes 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 →
55YearsYears 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 Sierra Nevada. See the full index history below.

Hermit Thrush In Sierra Nevada Population Forecast

If the recent trend holds, Hermit Thrush in Sierra Nevada is projected to stay roughly flat through 2030, near 2.6 (95% range 0.61–4.6). A 5-year backtest shows a typical error of ±82.2%, with 80% of held-out values landing inside the 95% band.

+7%Change by 2030TrendPercent 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 →
2.6Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.61–4.695% 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 →
±82.2%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, Hermit Thrush in Sierra Nevada is projected to stay roughly flat through 2030, near 2.6 (95% range 0.61–4.6). A 5-year backtest shows a typical error of ±82.2%, with 80% of held-out values landing inside the 95% band.19682030
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 →
20262.70.724.7
20272.70.694.7
20282.70.664.7
20292.60.644.6
20302.60.614.6

Routes In Sierra Nevada

Routes recording Hermit Thrush in Sierra Nevada.
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 →
WestvilleCALIFORNIA112025
GoumazCALIFORNIA112011
Lassen ParkCALIFORNIA101989
JohnsvilleCALIFORNIA102025
Tahoe NfCALIFORNIA61994
LumberyardCALIFORNIA52025
ChesterCALIFORNIA52017
Little TruckeeCALIFORNIA52025
StrawberryCALIFORNIA52019
DardanelleCALIFORNIA42019
RivertonCALIFORNIA42025
WoodfordsCALIFORNIA32025
DownievilleCALIFORNIA32021
Meadow ValleyCALIFORNIA32025
Forest HillCALIFORNIA32019
Pine MountainCALIFORNIA32017
Silver CityCALIFORNIA22013
Kings CanyonCALIFORNIA21988
Butte MeadowCALIFORNIA22014
Hat CreekCALIFORNIA22018
LakeshoreCALIFORNIA22011
Chaos CraterCALIFORNIA22019
WawonaCALIFORNIA22022
CrestviewCALIFORNIA22025
ChilcootCALIFORNIA22024

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.