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

Cerulean Warbler Population Trend in Wisconsin

All statesForest birds

Cerulean Warbler in Wisconsin has edged up: up 11% on the route-weighted index since 1970.

+11%Since 1970TrendPercent 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 →
25Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cerulean 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 →

No notable trend signals for Cerulean Warbler in Wisconsin. See the full index history below.

Cerulean Warbler Population Forecast in Wisconsin

If the recent trend holds, Cerulean Warbler in Wisconsin is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±100.4%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.02Projected 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 →
0.00–0.0695% 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 →
±100.4%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, Cerulean Warbler in Wisconsin is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±100.4%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.020.000.06
20260.020.000.06
20270.020.000.06
20280.020.000.06
20290.020.000.06

Cerulean Warbler Survey Routes in Wisconsin

Routes recording Cerulean 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 →
Eagle River319951995
Rolling Pr219761976
Chaffey119971997
Grand View120031972
Montreal119841984
Loraine119961968
Couderay119991994
Holway119891989
Crandon119971997
Amberg119991999
Esdaile120191974
Cochrane119771977
Hatfield119731973
Mather119881973
Elderon119961996
Saxeville119911989
Oconto Falls119751970
Newburg Crns120212021
Viroqua119881988
Rolling Grnd119961982
N Freedom120241976
Pardeeville120052005
Prairie Du Chien120232001
Paris119671967
Raymond120151972

Cerulean Warbler Population Trend in Other States

alabamaarkansasconnecticutgeorgiaillinoisindianakentuckylouisianamarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniatennesseevermontvirginiawest-virginia

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