BirdAnalyst
Species · BCR 13 · BBS 2026 Release · 1966–2025

Black-billed Cuckoo In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainForest birds

Black-billed Cuckoo in Lower Great Lakes / St. Lawrence Plain has collapsed: down 92% on the route-weighted index since 1968.

-92%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 →
82Routes 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 →
59YearsYears 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 collapsed in Lower Great Lakes / St. Lawrence Plain: down 91% on the route-weighted index since 1968.

Black-billed Cuckoo In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Black-billed Cuckoo in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2030, near 0.19 (95% range 0.00–0.68). A 5-year backtest shows a typical error of ±216.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2030TrendPercent 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 →
0.19Projected 2030 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 →
±216.9%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 Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2030, near 0.19 (95% range 0.00–0.68). A 5-year backtest shows a typical error of ±216.9%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20260.230.000.72
20270.220.000.71
20280.210.000.70
20290.200.000.69
20300.190.000.68

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Black-billed Cuckoo in Lower Great Lakes / St. Lawrence Plain.
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 →
Canadice LNEW-YORK52019
RushvilleNEW-YORK42022
DuanesburgNEW-YORK32022
BranchportNEW-YORK32022
MendonNEW-YORK32017
RhinebeckNEW-YORK22015
HighlandNEW-YORK22013
CatskillsNEW-YORK22009
GhentNEW-YORK22005
Ballston LkNEW-YORK21994
Mt MorrisNEW-YORK22016
CastileNEW-YORK22019
RandolphNEW-YORK22014
SheridanNEW-YORK21994
E YoungstownNEW-YORK22008
Cicero CtrNEW-YORK22022
ClintonNEW-YORK22013
ArgyleNEW-YORK22010
BalmatNEW-YORK22008
Harris HillNEW-YORK22018
MiddlefieldOHIO21995
HiramOHIO22000
AkeleyPENNSYLVANIA21979
HarrisvillePENNSYLVANIA22005
W ShokanNEW-YORK12013

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.