Black-billed Cuckoo
Black-billed Cuckoo has fallen sharply: down 75% 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 1,446 Breeding Bird Survey routes across 37 states, most concentrated in the Appalachian Mountains.
- Family
- Cuculidae · Forest birds
Notable Black-billed Cuckoo Trends
Black-billed Cuckoo has fallen sharply in surveyed states: down 75% 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 2029 — from 0.07 in 2024 to a central estimate of 0.00 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±76.6%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.03 | 0.00 | 0.20 |
| 2026 | 0.02 | 0.00 | 0.20 |
| 2027 | 0.01 | 0.00 | 0.19 |
| 2028 | 0.00 | 0.00 | 0.18 |
| 2029 | 0.00 | 0.00 | 0.18 |
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
| Alabama | insufficient data | n/a | 4 |
| Arkansas | insufficient data | n/a | 2 |
| Colorado | insufficient data | n/a | 1 |
| Connecticut | -71% | 1968 | 20 |
| Delaware | -57% | 1969 | 12 |
| Georgia | -77% | 1973 | 5 |
| Idaho | insufficient data | n/a | 1 |
| Illinois | -91% | 1968 | 62 |
| Indiana | -85% | 1968 | 45 |
| Iowa | -75% | 1969 | 36 |
| Kansas | -87% | 1969 | 44 |
| Kentucky | -8% | 1968 | 27 |
| Maine | -71% | 1971 | 58 |
| Maryland | -77% | 1968 | 53 |
| Massachusetts | +107% | 1969 | 32 |
| Michigan | -73% | 1968 | 101 |
| Minnesota | -20% | 1969 | 91 |
| Missouri | +99% | 1969 | 40 |
| Montana | -71% | 1971 | 29 |
| Nebraska | -84% | 1969 | 32 |
| New Hampshire | -73% | 1968 | 25 |
| New Jersey | -68% | 1968 | 30 |
| New York | -47% | 1968 | 123 |
| North Carolina | -82% | 1972 | 12 |
| North Dakota | -68% | 1969 | 48 |
| Ohio | -65% | 1968 | 71 |
| Oklahoma | -1% | 1969 | 9 |
| Pennsylvania | -73% | 1968 | 126 |
| Rhode Island | -76% | 1971 | 5 |
| South Dakota | -94% | 1969 | 46 |
| Tennessee | -16% | 1971 | 15 |
| Texas | insufficient data | n/a | 2 |
| Vermont | -82% | 1968 | 25 |
| Virginia | -90% | 1968 | 42 |
| West Virginia | -87% | 1968 | 56 |
| Wisconsin | -22% | 1968 | 97 |
| Wyoming | -88% | 1970 | 19 |
Black-billed Cuckoo Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Rockies | -92% | 1972 | 14 |
| Prairie Potholes | -76% | 1969 | 98 |
| Boreal Hardwood Transition | -21% | 1968 | 125 |
| Lower Great Lakes / St. Lawrence Plain | -80% | 1968 | 82 |
| Atlantic Northern Forest | -76% | 1968 | 129 |
| Southern Rockies / Colorado Plateau | -84% | 1970 | 3 |
| Badlands and Prairies | -86% | 1969 | 66 |
| Central Mixed Grass Prairie | -92% | 1969 | 48 |
| Eastern Tallgrass Prairie | -89% | 1968 | 188 |
| Prairie Hardwood Transition | -68% | 1968 | 147 |
| Central Hardwoods | -46% | 1968 | 60 |
| Southeastern Coastal Plain | -78% | 1974 | 8 |
| Appalachian Mountains | -65% | 1968 | 309 |
| Piedmont | -94% | 1968 | 35 |
| New England / Mid-Atlantic Coast | -88% | 1968 | 122 |
Black-billed Cuckoo Conservation Status
Our route-weighted index shows it down about 75% since 1968.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.