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

Black-billed Cuckoo Population Trend in Wisconsin

All statesGeneralists

Black-billed Cuckoo in Wisconsin has edged down: down 22% on the route-weighted index since 1968.

-22%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 →
97Routes 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 Black-billed Cuckoo 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 Black-billed Cuckoo in Wisconsin. See the full index history below.

Black-billed Cuckoo Population Forecast in Wisconsin

If the recent trend holds, Black-billed Cuckoo in Wisconsin is projected to fall about 37% by 2029 — from 0.72 in 2024 to a central estimate of 0.45 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±50.3%, with 100% of held-out values landing inside the 95% band.

-37%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 →
0.45Projected 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 →
0.00–1.395% 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 →
±50.3%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, Black-billed Cuckoo in Wisconsin is projected to fall about 37% by 2029 — from 0.72 in 2024 to a central estimate of 0.45 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±50.3%, 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 →
20250.540.001.4
20260.520.001.4
20270.490.001.4
20280.470.001.4
20290.450.001.3

Black-billed Cuckoo Survey Routes in Wisconsin

Routes recording Black-billed Cuckoo 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 →
Iron River2220241968
Chaffey1120221966
Gilman720231966
Dresser320181966
Union Twp320241966
Amberg320241980
Wis Rapids320231969
Stevens Pt320231970
Mount Horeb319861971
Loraine220211966
Cumberland220231966
Exeland220221968
Rib Lake220221966
Crandon220191967
Wausaukee220241980
Washington I220191971
Mather220231966
Elderon220151970
Newburg Crns220181971
Rolling Grnd220241968
Pardeeville220191967
Rolling Pr220151967
Hazel Green220011966
Raymond220051974
Amnicon Falls220241999

Black-billed Cuckoo Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-dakotatennesseetexasvermontvirginiawest-virginiawyoming

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