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Species · Wisconsin · BBS 2025 Release · 1966–2024

Hermit Thrush Population Trend in Wisconsin

All statesForest birds

Hermit Thrush in Wisconsin has surged: up 105% on the route-weighted index since 1968.

+105%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 →
49Routes 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 →
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 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 105% 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 2029 — from 2.5 in 2024 to a central estimate of 4.5 (95% range 2.7–6.4). A 5-year backtest shows a typical error of ±116.3%, with 20% of held-out values landing inside the 95% band.

+82%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 →
4.5Projected 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 →
2.7–6.495% 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 →
±116.3%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 Wisconsin is projected to rise about 82% by 2029 — from 2.5 in 2024 to a central estimate of 4.5 (95% range 2.7–6.4). A 5-year backtest shows a typical error of ±116.3%, 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 →
20254.32.56.2
20264.42.56.2
20274.42.66.3
20284.52.66.3
20294.52.76.4

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
Land O' Lakes 22320242017
Conover2220241998
Eagle River2120241966
Popple River1920241966
Cavour1420241998
Mellen1120241998
Shanagolden1020241966
Union Twp1020241975
Grand View920241966
Montreal920241968
Hatfield919981977
Irma620241968
Hollister620241967
Amberg620241980
Chaffey520241966
Rib Lake520241970
Mcnaughton520241966
Flambeau520241998
Gilman420161981
Mather420191986
Merrill320081966
Crandon320241967
Washington I320191994
Rhinelander320231998

Hermit Thrush Population Trend in Other States

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

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