BirdAnalyst
Species · BCR 29 · BBS 2025 Release · 1966–2024

Black-billed Cuckoo In Piedmont

All regionsPiedmontGeneralists

Black-billed Cuckoo in Piedmont has collapsed: down 94% on the route-weighted index since 1968.

-94%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 →
35Routes 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 →
43YearsYears 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 Piedmont: down 94% on the route-weighted index since 1968.

Black-billed Cuckoo In Piedmont Population Forecast

If the recent trend holds, Black-billed Cuckoo in Piedmont is projected to stay roughly flat through 2026, near 0.00 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±614.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2026TrendPercent 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 →
0.00Projected 2026 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1495% 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 →
±614.2%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 Piedmont is projected to stay roughly flat through 2026, near 0.00 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±614.2%, with 100% of held-out values landing inside the 95% band.19662026
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 →
20220.000.000.14
20230.000.000.14
20240.000.000.14
20250.000.000.14
20260.000.000.14

Routes In Piedmont

Routes recording Black-billed Cuckoo in Piedmont.
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 →
Upper XrdsMARYLAND42004
EmmitsburgMARYLAND31987
Doe RunPENNSYLVANIA31991
Carters BrdgVIRGINIA31981
Bachman MillMARYLAND21984
CollegevillePENNSYLVANIA21981
TaylorstownVIRGINIA21985
TrymeVIRGINIA22011
ShipmanVIRGINIA21995
WhitesburgGEORGIA11993
Silver SpgMARYLAND11989
OlneyMARYLAND11981
WarfieldsbrgMARYLAND11990
FowblesburgMARYLAND12009
EkloMARYLAND11993
RandallstownMARYLAND11989
Van BibberMARYLAND12000
TheodoreMARYLAND12004
IjamsvilleMARYLAND12012
SandbrookNEW-JERSEY12017
CrotonNEW-JERSEY12007
Croton 2NEW-JERSEY12016
CopelandNORTH-CAROLINA11975
Mt GretnaPENNSYLVANIA11993
PottstownPENNSYLVANIA11976

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