BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Hermit Thrush In BCR 4

All regionsBCR 4Forest birds

Hermit Thrush in BCR 4 has risen sharply: up 72% on the route-weighted index since 1976.

+72%Since 1976TrendPercent 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 →
59Routes 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 →
47YearsYears 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 risen sharply in BCR 4: up 72% on the route-weighted index since 1976.

Hermit Thrush In BCR 4 Population Forecast

If the recent trend holds, Hermit Thrush in BCR 4 is projected to rise about 109% by 2029 — from 2.4 in 2024 to a central estimate of 5.0 (95% range 0.86–9.1). A 5-year backtest shows a typical error of ±79.7%, with 100% of held-out values landing inside the 95% band.

+109%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 →
5.0Projected 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 →
0.86–9.195% 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 →
±79.7%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 BCR 4 is projected to rise about 109% by 2029 — from 2.4 in 2024 to a central estimate of 5.0 (95% range 0.86–9.1). A 5-year backtest shows a typical error of ±79.7%, 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 →
20255.00.859.1
20265.00.859.1
20275.00.869.1
20285.00.869.1
20295.00.869.1

Routes In BCR 4

Routes recording Hermit Thrush in BCR 4.
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 →
HomerALASKA331982
MatanuskaALASKA331983
Anchor RiverALASKA182024
CohoeALASKA142023
Pinoche Tral (Short)ALASKA121984
EagleALASKA112024
ToklatALASKA102024
KachemakALASKA92024
KalifonskyALASKA82023
Kenny LakeALASKA72024
Seven LakesALASKA62023
NorthwayALASKA52023
Chena Hot SpALASKA51990
Mt. FairplayALASKA52024
Chatanika RALASKA42023
MonahanALASKA42021
Chena RiverALASKA41988
L SalchaALASKA42021
WasillaALASKA41983
Anvik RiverALASKA42024
LivengoodALASKA32021
SlanaALASKA32022
Tower BluffsALASKA32016
TonsinaALASKA32021
Hatcher PassALASKA32024

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