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Species · BCR 4 · BBS 2026 Release · 1966–2025

Hermit Thrush In BCR 4

All regionsBCR 4Forest birds

Hermit Thrush in BCR 4 has risen sharply: up 62% on the route-weighted index since 1976.

+62%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 →
48YearsYears 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 62% 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 62% by 2030 — from 3.0 in 2025 to a central estimate of 4.8 (95% range 0.67–8.9). A 5-year backtest shows a typical error of ±95.3%, with 100% of held-out values landing inside the 95% band.

+62%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 →
4.8Projected 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 →
0.67–8.995% 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 →
±95.3%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 62% by 2030 — from 3.0 in 2025 to a central estimate of 4.8 (95% range 0.67–8.9). A 5-year backtest shows a typical error of ±95.3%, with 100% 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 →
20264.80.689.0
20274.80.689.0
20284.80.688.9
20294.80.678.9
20304.80.678.9

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 RiverALASKA252025
KachemakALASKA172025
CohoeALASKA142023
Seven LakesALASKA142025
Pinoche Tral (Short)ALASKA121984
ToklatALASKA102024
EagleALASKA82025
Kenny LakeALASKA72025
Donelly DomeALASKA72025
Chena Hot SpALASKA51990
SavageALASKA52025
Mt. FairplayALASKA52025
Nabesna RoadALASKA52025
Chena RiverALASKA41988
WasillaALASKA41983
Anvik RiverALASKA42024
LivengoodALASKA32021
SlanaALASKA32022
Tower BluffsALASKA32016
ChistochinaALASKA32025
TonsinaALASKA32021
Unalakleet RiverALASKA32023
Manley Ht SpALASKA32022

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