Black-billed Cuckoo Population Analysis
Black-billed Cuckoo has collapsed: down 78% on the route-weighted index since 1968.
About the Black-billed Cuckoo
The Black-billed Cuckoo (Coccyzus erythropthalmus) is a North American member of the Cuckoos, Roadrunners & Anis (Cuculidae). In this analysis it is grouped with the forest birds.
- Size
- 10.5–22 in long (27–56 cm) — a slender, long-tailed bird (typical for the family)
- Habitat
- Woodlands and forest edges, including wooded suburbs and parks.
- Diet
- Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
- Range
- Recorded on 1,449 Breeding Bird Survey routes across 37 states, most concentrated in the Appalachian Mountains.
- Family
- Cuculidae · Forest birds
Notable Black-billed Cuckoo TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →
Black-billed Cuckoo has collapsed in surveyed states: down 78% on the route-weighted index since 1968.
Black-billed Cuckoo Population Forecast
If the recent trend holds, Black-billed Cuckoo is projected to fall about 100% by 2030 — from 0.07 in 2025 to a central estimate of 0.00 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±82.7%, with 100% of held-out values landing inside the 95% band.
Where the Black-billed Cuckoo Is Detected
BBS routes recording Black-billed Cuckoo, sized by most recent count.
Black-billed Cuckoo Population Trend by State
Black-billed Cuckoo Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
Black-billed Cuckoo Conservation Status
Our route-weighted index shows it down about 78% since 1968.
Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.