BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Black-billed Cuckoo In Appalachian Mountains

All regionsAppalachian MountainsGeneralists

Black-billed Cuckoo in Appalachian Mountains has fallen sharply: down 65% on the route-weighted index since 1968.

-65%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 →
309Routes 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 Appalachian Mountains: down 65% on the route-weighted index since 1968.

Black-billed Cuckoo In Appalachian Mountains Population Forecast

If the recent trend holds, Black-billed Cuckoo in Appalachian Mountains is projected to rise about 52% by 2029 — from 0.10 in 2024 to a central estimate of 0.16 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±52%, with 100% of held-out values landing inside the 95% band.

+52%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 →
0.16Projected 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 →
0.00–0.4895% 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 →
±52%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 Appalachian Mountains is projected to rise about 52% by 2029 — from 0.10 in 2024 to a central estimate of 0.16 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±52%, 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 →
20250.190.000.51
20260.180.000.50
20270.170.000.49
20280.170.000.48
20290.160.000.48

Routes In Appalachian Mountains

Routes recording Black-billed Cuckoo in Appalachian Mountains.
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 →
Big FlatPENNSYLVANIA111981
RasselasPENNSYLVANIA102022
BetulaPENNSYLVANIA82022
SomersNEW-YORK71970
AdamsvilleOHIO71982
LaurensNEW-YORK62009
Shawnee S.F. 2OHIO62015
StarlightPENNSYLVANIA61992
Mt HopeNEW-YORK51982
MeridaleNEW-YORK52024
WyalusingPENNSYLVANIA52023
Sproul Sf-BPENNSYLVANIA52023
WarwickNEW-YORK41973
Greasy RidgeOHIO41991
RydePENNSYLVANIA42005
JeannettePENNSYLVANIA42016
BramwellWEST-VIRGINIA41980
Pt PleasantWEST-VIRGINIA41995
ClintonWEST-VIRGINIA42019
MckeeKENTUCKY31978
WolfsvilleMARYLAND31998
MidvaleNEW-JERSEY31980
DoverNEW-JERSEY32015
DrydenNEW-YORK32023
Coal RunOHIO31991

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