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Species · Wisconsin · BBS 2026 Release · 1966–2025

Hermit Thrush Population Trend in Wisconsin

All statesForest birds

Hermit Thrush in Wisconsin has surged: up 111% on the route-weighted index since 1968.

+111%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 →
50Routes 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 →
59YearsYears 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 WisconsinNotable 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 Wisconsin: up 111% on the route-weighted index since 1968.

Hermit Thrush Population Forecast in Wisconsin

If the recent trend holds, Hermit Thrush in Wisconsin is projected to rise about 82% by 2030 — from 2.4 in 2025 to a central estimate of 4.4 (95% range 2.5–6.3). A 5-year backtest shows a typical error of ±135.8%, with 0% of held-out values landing inside the 95% band.

+82%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 →
4.4Projected 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 →
2.5–6.395% 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 →
±135.8%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 Wisconsin is projected to rise about 82% by 2030 — from 2.4 in 2025 to a central estimate of 4.4 (95% range 2.5–6.3). A 5-year backtest shows a typical error of ±135.8%, with 0% of held-out values landing inside the 95% band.19662030
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 →
20264.22.36.1
20274.32.46.2
20284.32.46.2
20294.42.56.3
20304.42.56.3

Hermit Thrush Survey Routes in Wisconsin

Routes recording Hermit Thrush in Wisconsin.
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 →
Land O Lakes4020161967
Conover3720251998
Land O' Lakes 22720252017
Popple River2020251966
Eagle River1520251966
Hatfield919981977
Grand View820251966
Shanagolden820251966
Flambeau820251998
Cavour820251998
Montreal720251968
Chaffey620251966
Union Twp620251975
Rib Lake520251970
Mcnaughton520241966
Mellen520251998
Weirgor Springs520251999
Bayfield420251967
Amberg420251980
Mather420191986
Merrill320081966
Crandon320251967
Hollister320251967
Washington I320191994
Rhinelander320231998

Hermit Thrush Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahoindianamainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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