BirdAnalyst
Species · Wisconsin · BBS 2025 Release · 1966–2024

Winter Wren Population Trend in Wisconsin

All statesForest birds

Winter Wren in Wisconsin has surged: up 99% on the route-weighted index since 1968.

+99%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 Winter Wren 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 →

Winter Wren has surged in Wisconsin: up 99% on the route-weighted index since 1968.

Winter Wren Population Forecast in Wisconsin

If the recent trend holds, Winter Wren in Wisconsin is projected to rise about 60% by 2029 — from 0.59 in 2024 to a central estimate of 0.95 (95% range 0.31–1.6). A 5-year backtest shows a typical error of ±93%, with 80% of held-out values landing inside the 95% band.

+60%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 →
0.95Projected 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 →
0.31–1.695% 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 →
±93%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, Winter Wren in Wisconsin is projected to rise about 60% by 2029 — from 0.59 in 2024 to a central estimate of 0.95 (95% range 0.31–1.6). A 5-year backtest shows a typical error of ±93%, with 80% 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 →
20250.930.281.6
20260.940.291.6
20270.940.301.6
20280.950.301.6
20290.950.311.6

Winter Wren Survey Routes in Wisconsin

Routes recording Winter Wren 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 Lakes1420161967
Washington I920241967
Eagle River720241966
Shanagolden520241969
Mellen520241998
Cavour520241998
Hollister420231968
Land O' Lakes 2420242017
Popple River320241966
Esdaile319751975
Chaffey220211969
Grand View220241966
Bayfield220241970
Amberg220231980
Wis Rapids220222022
Amnicon Falls220231998
Casco220231976
Flambeau220241998
Iron River120221967
Minong119961969
Montreal120241979
Union Twp120172017
Loraine119791979
Cumberland119981997
Weyerhauser119951995

Winter Wren Population Trend in Other States

connecticutmainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniatennesseevermontvirginiawest-virginia

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