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

Yellow Warbler Population Trend in Wisconsin

All statesForest birds

Yellow Warbler in Wisconsin has risen sharply: up 68% on the route-weighted index since 1968.

+68%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 →
98Routes 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 Yellow 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 →

Yellow Warbler has risen sharply in Wisconsin: up 68% on the route-weighted index since 1968.

Yellow Warbler Population Forecast in Wisconsin

If the recent trend holds, Yellow Warbler in Wisconsin is projected to fall about 17% by 2030 — from 10 in 2025 to a central estimate of 8.4 (95% range 6.7–10). A 5-year backtest shows a typical error of ±10.2%, with 80% of held-out values landing inside the 95% band.

-17%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 →
8.4Projected 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 →
6.7–1095% 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 →
±10.2%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, Yellow Warbler in Wisconsin is projected to fall about 17% by 2030 — from 10 in 2025 to a central estimate of 8.4 (95% range 6.7–10). A 5-year backtest shows a typical error of ±10.2%, 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 →
20268.16.49.9
20278.26.510.0
20288.36.510
20298.36.610
20308.46.710

Yellow Warbler Survey Routes in Wisconsin

Routes recording Yellow 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 →
Gilman4720251966
Cumberland4420251966
Fall River3620251967
Loraine2920251966
Bashaw2820251998
Omro 22520252002
Grimms2520211998
Wis Rapids2420231966
Pardeeville2420251967
Viroqua2120241966
Mather2020231966
Omro2020011966
Weirgor Springs2020251999
Exeland1620251968
Gilmanton1620251966
Weyerhauser1520251966
Eden1520251966
Hebron1520251966
Stetsonville1520251990
Esdaile1420251966
New Lisbon1420251967
Brownsville1420251966
Holland1420251999
Phillips1320251966
Merrill1320251966

Yellow Warbler Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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