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Species · Wisconsin · BBS 2025 Release · 1966–2024

Blue-winged Warbler Population Trend in Wisconsin

All statesForest birds

Blue-winged Warbler in Wisconsin has surged: up 282% on the route-weighted index since 1968.

+282%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 →
62Routes 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 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 282% 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 fall about 19% by 2029 — from 0.62 in 2024 to a central estimate of 0.50 (95% range 0.33–0.67). A 5-year backtest shows a typical error of ±18.5%, with 60% of held-out values landing inside the 95% band.

-19%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 →
0.50Projected 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 →
0.33–0.6795% 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 →
±18.5%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 fall about 19% by 2029 — from 0.62 in 2024 to a central estimate of 0.50 (95% range 0.33–0.67). A 5-year backtest shows a typical error of ±18.5%, with 60% 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 →
20250.470.300.64
20260.480.310.65
20270.480.320.65
20280.490.320.66
20290.500.330.67

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 →
Pigeon Creek920242007
Gilmanton720241970
Mather720231979
N Freedom720241966
Cumberland420242007
Cochrane420221966
Cadott420241999
Clintonville420161989
Esdaile320241975
Viroqua320241966
Prairie Du Chien320212000
Highland220181999
Irma220222022
Meridean220221998
Amberg220182004
Saxeville220241984
Gresham220242013
Briggsville220132001
Weirgor Springs220242024
Grand View120111973
Hudson120241966
Dresser120242011
Union Twp119921992
Loraine120171995
Weyerhauser120242009

Blue-winged Warbler Population Trend in Other States

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

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