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Species · Wisconsin · BBS 2025 Release · 1966–2024

Connecticut Warbler Population Trend in Wisconsin

All statesForest birds

Connecticut Warbler in Wisconsin has declined: down 37% on the route-weighted index since 1969.

-37%Since 1969TrendPercent 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 →
26Routes 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 →
49YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Connecticut 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 Connecticut Warbler in Wisconsin. See the full index history below.

Connecticut Warbler Population Forecast in Wisconsin

If the recent trend holds, Connecticut Warbler in Wisconsin is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±356.1%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2095% 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 →
±356.1%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, Connecticut Warbler in Wisconsin is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±356.1%, with 100% of held-out values landing inside the 95% band.19672028
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 →
20240.030.000.22
20250.030.000.21
20260.030.000.21
20270.020.000.21
20280.020.000.20

Connecticut Warbler Survey Routes in Wisconsin

Routes recording Connecticut 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 →
Montreal319801976
Bayfield219831970
Shanagolden219861980
Popple River219841971
Rhinelander219981998
Chaffey120111980
Iron River120111989
Minong120231967
Grand View120011971
Land O Lakes120001981
Union Twp120071975
Rib Lake120071984
Irma119891986
Mcnaughton120041968
Eagle River119761972
Crandon119901990
Amberg119961996
Wausaukee119891989
Mather119771970
Oconto Falls119741972
Amnicon Falls120101999
Mellen119981998
Conover120071999
Bashaw120042002
Flambeau120072007

Connecticut Warbler Population Trend in Other States

michiganminnesotanew-york

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