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

Blue-winged Warbler Population Trend in Wisconsin

All statesForest birds

Blue-winged Warbler in Wisconsin has surged: up 326% on the route-weighted index since 1968.

+326%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 →
63Routes 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 Blue-winged Warbler 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 →

Blue-winged Warbler has surged in Wisconsin: up 326% on the route-weighted index since 1968.

Blue-winged Warbler Population Forecast in Wisconsin

If the recent trend holds, Blue-winged Warbler in Wisconsin is projected to stay roughly flat through 2030, near 0.51 (95% range 0.34–0.68). A 5-year backtest shows a typical error of ±14.6%, with 80% of held-out values landing inside the 95% band.

-10%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 →
0.51Projected 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 →
0.34–0.6895% 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 →
±14.6%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, Blue-winged Warbler in Wisconsin is projected to stay roughly flat through 2030, near 0.51 (95% range 0.34–0.68). A 5-year backtest shows a typical error of ±14.6%, with 80% 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 →
20260.490.320.66
20270.490.320.66
20280.500.330.67
20290.510.340.68
20300.510.340.68

Blue-winged Warbler Survey Routes in Wisconsin

Routes recording Blue-winged Warbler 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 →
Gilmanton1120251970
Mather720231979
Cumberland420242007
Esdaile420251975
Cochrane420221966
Pigeon Creek320252007
Manawa320251995
Viroqua320241966
Kendall320251970
N Freedom320251966
Prairie Du Chien320212000
Weirgor Springs320252024
Hudson220251966
Highland220181999
Irma220222022
Meridean220221998
Amberg220182004
Saxeville220241984
Eden220251976
Briggsville220132001
Grand View120111973
Dresser120242011
Union Twp119921992
Loraine120251995
Weyerhauser120242009

Blue-winged Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawaregeorgiaillinoisindianaiowakentuckymarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandtennesseevermontvirginiawest-virginia

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