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Species · Wisconsin · BBS 2026 Release · 1966–2025

Warbling Vireo Population Trend in Wisconsin

All statesForest birds

Warbling Vireo in Wisconsin has edged down: down 14% on the route-weighted index since 1968.

-14%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 →
95Routes 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 Warbling Vireo 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 →

No notable trend signals for Warbling Vireo in Wisconsin. See the full index history below.

Warbling Vireo Population Forecast in Wisconsin

If the recent trend holds, Warbling Vireo in Wisconsin is projected to fall about 26% by 2030 — from 4.5 in 2025 to a central estimate of 3.3 (95% range 1.9–4.8). A 5-year backtest shows a typical error of ±26.4%, with 80% of held-out values landing inside the 95% band.

-26%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 →
3.3Projected 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 →
1.9–4.895% 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 →
±26.4%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, Warbling Vireo in Wisconsin is projected to fall about 26% by 2030 — from 4.5 in 2025 to a central estimate of 3.3 (95% range 1.9–4.8). A 5-year backtest shows a typical error of ±26.4%, 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 →
20263.31.94.8
20273.31.94.8
20283.31.94.8
20293.31.94.8
20303.31.94.8

Warbling Vireo Survey Routes in Wisconsin

Routes recording Warbling Vireo 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 →
Kendall2020251967
Grimms1920211998
Pardeeville1720251968
Viroqua1620241966
Trempealeau1420251966
River Falls1420251998
Fall River1320251966
Hazel Green1320251966
Wiota1320251966
Paris1320251966
Esdaile1220251966
N Freedom1220251966
Prairie Du Chien1220251998
Cochrane1120251966
New Lisbon1020251967
Beloit1020251998
Gilmanton820251966
Stratford820251966
Brownsville820251966
N Andover820251967
Hebron820251966
Highland820251998
Annaton820251998
Eagle River720101966
Omro 2720252002

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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