BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Hermit Thrush In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionForest birds

Hermit Thrush in Boreal Hardwood Transition has risen sharply: up 56% on the route-weighted index since 1968.

+56%Since 1968TrendPercent 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 →
124Routes 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 →
58YearsYears 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 Boreal Hardwood Transition: up 56% on the route-weighted index since 1968.

Hermit Thrush In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Hermit Thrush in Boreal Hardwood Transition is projected to rise about 59% by 2029 — from 8.3 in 2024 to a central estimate of 13 (95% range 8.8–17). A 5-year backtest shows a typical error of ±82.4%, with 20% of held-out values landing inside the 95% band.

+59%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 →
13Projected 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 →
8.8–1795% 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 →
±82.4%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 Boreal Hardwood Transition is projected to rise about 59% by 2029 — from 8.3 in 2024 to a central estimate of 13 (95% range 8.8–17). A 5-year backtest shows a typical error of ±82.4%, with 20% of held-out values landing inside the 95% band.19662029
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 →
2025138.317
2026138.417
2027138.617
2028138.717
2029138.817

Routes In Boreal Hardwood Transition

Routes recording Hermit Thrush in Boreal Hardwood Transition.
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 →
Betchler LksMICHIGAN542024
SidnawMICHIGAN442024
Land O LakesWISCONSIN402016
GooseneckMICHIGAN372010
Cluster LakesMICHIGAN342010
Gibbs CityMICHIGAN272024
Brocky LakeMICHIGAN272024
EnsignMICHIGAN262010
Nett LakeMINNESOTA262024
MuskallongeMICHIGAN252024
Pine RiverMICHIGAN252021
Scott'S MarshMICHIGAN252010
Big Island LakeMICHIGAN252010
Land O' Lakes 2WISCONSIN232024
ConoverWISCONSIN222024
Eagle RiverWISCONSIN212024
Seney NwrMICHIGAN202024
Popple RiverWISCONSIN192024
RacoMICHIGAN182024
MareniscoMICHIGAN172019
Red OakMICHIGAN162022
JordanMINNESOTA162023
CreightonMICHIGAN152023
Sawbill LndgMINNESOTA152024
Brush CreekMICHIGAN142016

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