BirdAnalyst
Species · North Carolina · BBS 2025 Release · 1966–2024

Black-billed Cuckoo Population Trend in North Carolina

All statesGeneralists

Black-billed Cuckoo in North Carolina has collapsed: down 82% on the route-weighted index since 1972.

-82%Since 1972TrendPercent 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 →
12Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
21YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-billed Cuckoo Trends in North CarolinaNotable 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 North Carolina: down 82% on the route-weighted index since 1972.

Black-billed Cuckoo Population Forecast in North Carolina

If the recent trend holds, Black-billed Cuckoo in North Carolina is projected to stay roughly flat through 2020, near 0.00 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±44.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2020TrendPercent 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 2020 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0795% 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 →
±44.7%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 North Carolina is projected to stay roughly flat through 2020, near 0.00 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±44.7%, with 100% of held-out values landing inside the 95% band.19702020
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 →
20160.010.000.07
20170.010.000.07
20180.000.000.07
20190.000.000.07
20200.000.000.07

Black-billed Cuckoo Survey Routes in North Carolina

Routes recording Black-billed Cuckoo in North Carolina.
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 →
Milltail Cr619971997
Todd120152015
Sheep Ridge120142013
Waterville120081998
Busick119981994
Table Rock119961995
Pinelog120072007
Oteen119881988
Copeland119751970
Marshall120041995
Cullowhee119791978
Linville120032003

Black-billed Cuckoo Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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