BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Black-billed Cuckoo In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGeneralists

Black-billed Cuckoo in Prairie Hardwood Transition has fallen sharply: down 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 →
147Routes In RegionSurvey 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 SignalsNotable 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 declinecomputed 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 →

Black-billed Cuckoo has fallen sharply in Prairie Hardwood Transition: down 68% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Black-billed Cuckoo in Prairie Hardwood Transition is projected to fall about 14% by 2029 — from 0.27 in 2024 to a central estimate of 0.23 (95% range 0.00–0.68). A 5-year backtest shows a typical error of ±21.7%, with 100% of held-out values landing inside the 95% band.

-14%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 →
0.23Projected 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 →
0.00–0.6895% 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 →
±21.7%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 Prairie Hardwood Transition is projected to fall about 14% by 2029 — from 0.27 in 2024 to a central estimate of 0.23 (95% range 0.00–0.68). A 5-year backtest shows a typical error of ±21.7%, 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 →
20250.290.000.75
20260.280.000.73
20270.260.000.71
20280.250.000.70
20290.230.000.68

Routes In Prairie Hardwood Transition

Routes recording Black-billed Cuckoo in Prairie Hardwood Transition.
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 →
GuilfordILLINOIS42023
GalesburgMICHIGAN42015
MontereyMICHIGAN42015
HungerfordMICHIGAN42024
Barry S.G.A. 2MICHIGAN42019
St CharlesMICHIGAN31991
TyreMICHIGAN31996
Allegan WmaMICHIGAN32017
DresserWISCONSIN32018
Wis RapidsWISCONSIN32023
Stevens PtWISCONSIN32023
Mount HorebWISCONSIN31986
KewannaINDIANA22007
Packertown 2INDIANA22008
LawrenceMICHIGAN22009
Big RapidsMICHIGAN21990
HowardsvilleMICHIGAN22023
No BradleyMICHIGAN22022
PettysvilleMICHIGAN21979
Chippewa Lk.MICHIGAN22008
AlmenaMICHIGAN22009
ChatfieldMINNESOTA21977
Caledonia 2MINNESOTA22018
Sherburne NrMINNESOTA22024
LoraineWISCONSIN22021

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