Species · BBS 2025 Release · 1966–2024

Black-billed Cuckoo

CuculidaeForest birdsCoccyzus erythropthalmus

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 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 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.

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.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 →
20250.030.000.20
20260.020.000.20
20270.010.000.19
20280.000.000.18
20290.000.000.18

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

Black-billed Cuckoo population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alabamainsufficient datan/a4
Arkansasinsufficient datan/a2
Coloradoinsufficient datan/a1
Connecticut-71%196820
Delaware-57%196912
Georgia-77%19735
Idahoinsufficient datan/a1
Illinois-91%196862
Indiana-85%196845
Iowa-75%196936
Kansas-87%196944
Kentucky-8%196827
Maine-71%197158
Maryland-77%196853
Massachusetts+107%196932
Michigan-73%1968101
Minnesota-20%196991
Missouri+99%196940
Montana-71%197129
Nebraska-84%196932
New Hampshire-73%196825
New Jersey-68%196830
New York-47%1968123
North Carolina-82%197212
North Dakota-68%196948
Ohio-65%196871
Oklahoma-1%19699
Pennsylvania-73%1968126
Rhode Island-76%19715
South Dakota-94%196946
Tennessee-16%197115
Texasinsufficient datan/a2
Vermont-82%196825
Virginia-90%196842
West Virginia-87%196856
Wisconsin-22%196897
Wyoming-88%197019

Black-billed Cuckoo Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Black-billed Cuckoo population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Rockies-92%197214
Prairie Potholes-76%196998
Boreal Hardwood Transition-21%1968125
Lower Great Lakes / St. Lawrence Plain-80%196882
Atlantic Northern Forest-76%1968129
Southern Rockies / Colorado Plateau-84%19703
Badlands and Prairies-86%196966
Central Mixed Grass Prairie-92%196948
Eastern Tallgrass Prairie-89%1968188
Prairie Hardwood Transition-68%1968147
Central Hardwoods-46%196860
Southeastern Coastal Plain-78%19748
Appalachian Mountains-65%1968309
Piedmont-94%196835
New England / Mid-Atlantic Coast-88%1968122

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.