BirdAnalyst
Species · Alaska · BBS 2026 Release · 1966–2025

Hermit Thrush Population Trend in Alaska

All statesForest birds

Hermit Thrush in Alaska has surged: up 142% on the route-weighted index since 1972.

+142%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 →
107Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Hermit Thrush Trends in AlaskaNotable 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 Alaska: up 142% on the route-weighted index since 1972.

Hermit Thrush Population Forecast in Alaska

If the recent trend holds, Hermit Thrush in Alaska is projected to rise about 51% by 2030 — from 13 in 2025 to a central estimate of 20 (95% range 11–28). A 5-year backtest shows a typical error of ±44.5%, with 100% of held-out values landing inside the 95% band.

+51%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 →
20Projected 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 →
11–2895% 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 →
±44.5%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 Alaska is projected to rise about 51% by 2030 — from 13 in 2025 to a central estimate of 20 (95% range 11–28). A 5-year backtest shows a typical error of ±44.5%, 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 →
20261910.028
2027191028
2028191028
2029191128
2030201128

Hermit Thrush Survey Routes in Alaska

Routes recording Hermit Thrush in Alaska.
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 →
Yakutat (Short)11119841984
Thompson Pas10220251983
Kodiak 28120251985
Copper River7920111993
Yakutat7620251993
Harlequin L.7620241993
Chiniak7520251985
Chichagof Is7420241994
Cordova6320241983
Hoonah6320241993
Thorne Bay 26220252013
Thorne Bay6020121989
Petersburg5919871987
Seward5319921982
Mitkof Isle4920251988
Kodiak4819841983
Whale Pass4520241997
Zimovia Strt3920251988
Zarembo3620241993
Hope3420251985
Homer3319821977
Matanuska3319831982
Haines3120251972
Kuiu Island3020102004
Beaver Creek2719771977

Hermit Thrush Population Trend in Other States

arizonacaliforniacoloradoconnecticutidahoindianamainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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