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

Wood Thrush Population Trend in Wisconsin

All statesForest birds

Wood Thrush in Wisconsin has surged: up 101% on the route-weighted index since 1968.

+101%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 →
96Routes 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 Wood 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 →

Wood Thrush has surged in Wisconsin: up 101% on the route-weighted index since 1968.

Wood Thrush Population Forecast in Wisconsin

If the recent trend holds, Wood Thrush in Wisconsin is projected to fall about 41% by 2030 — from 3.3 in 2025 to a central estimate of 2.0 (95% range 1.1–2.8). A 5-year backtest shows a typical error of ±38%, with 40% of held-out values landing inside the 95% band.

-41%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 →
2.0Projected 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 →
1.1–2.895% 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 →
±38%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, Wood Thrush in Wisconsin is projected to fall about 41% by 2030 — from 3.3 in 2025 to a central estimate of 2.0 (95% range 1.1–2.8). A 5-year backtest shows a typical error of ±38%, with 40% 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 →
20261.91.12.7
20271.91.12.8
20281.91.12.8
20291.91.12.8
20302.01.12.8

Wood Thrush Survey Routes in Wisconsin

Routes recording Wood 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 →
Weirgor Springs3320251999
Popple River2020251967
Mellen1820251998
Wausaukee1320251980
Cavour1120252000
Amnicon Falls1020251998
Mather920231966
Flambeau920251999
Land O Lakes820091969
Hatfield819981971
Gresham820251998
Minong720251967
Rib Lake720251966
Union Twp620251969
Couderay620251969
Crandon620251967
Hollister620251967
Cadott620251966
Stevens Pt620231966
Bashaw620252000
River Falls620252005
Cumberland520251967
Chaffey420251967
Bayfield420251972
Amberg420251980

Wood Thrush Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginia

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