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

Yellow Warbler Population Trend in Wisconsin

All statesForest birds

Yellow Warbler in Wisconsin has risen sharply: up 55% on the route-weighted index since 1968.

+55%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 →
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 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 55% 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 stay roughly flat through 2029, near 8.2 (95% range 6.5–9.8). A 5-year backtest shows a typical error of ±6.1%, with 100% of held-out values landing inside the 95% band.

-1%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 →
8.2Projected 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 →
6.5–9.895% 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 →
±6.1%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 stay roughly flat through 2029, near 8.2 (95% range 6.5–9.8). A 5-year backtest shows a typical error of ±6.1%, with 100% 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 →
20257.96.29.6
20268.06.39.6
20278.06.49.7
20288.16.49.8
20298.26.59.8

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 →
Gilman4320241966
Cumberland3620241966
Dresser2720241966
Fall River2620241967
Grimms2520211998
Exeland2420241968
Wis Rapids2420231966
Weirgor Springs2420241999
Gilmanton2120241966
Viroqua2120241966
Mather2020231966
Omro2020011966
Paris1720241967
Highland1720241998
Omro 21620242002
Pardeeville1320241967
Eden1320241966
Hebron1320241966
Mukwonago 21320242005
Trempealeau1220241966
Manawa1220241966
N Freedom1220241966
Brownsville1220241966
Buena Vista1220241998
Annaton1220242003

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 2026-05-22.