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Species · Massachusetts · BBS 2026 Release · 1966–2025

Black-billed Cuckoo Population Trend in Massachusetts

All statesForest birds

Black-billed Cuckoo in Massachusetts has declined: down 40% on the route-weighted index since 1969.

-40%Since 1969TrendPercent 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 →
32Routes 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 →
54YearsYears 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 MassachusettsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Black-billed Cuckoo in Massachusetts. See the full index history below.

Black-billed Cuckoo Population Forecast in Massachusetts

If the recent trend holds, Black-billed Cuckoo in Massachusetts is projected to rise about 166% by 2030 — from 0.19 in 2025 to a central estimate of 0.50 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±281%, with 100% of held-out values landing inside the 95% band.

+166%Change by 2030TrendPercent 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 →
0.50Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.495% 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 →
±281%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 Massachusetts is projected to rise about 166% by 2030 — from 0.19 in 2025 to a central estimate of 0.50 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±281%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.500.001.4
20270.500.001.4
20280.500.001.4
20290.500.001.4
20300.500.001.4

Black-billed Cuckoo Survey Routes in Massachusetts

Routes recording Black-billed Cuckoo in Massachusetts.
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 →
E Dennis520061969
Prattville320181968
E Pepperell319941974
Wellfleet 2320172016
Newburyport220151968
Chesterfield220181970
Ware River220191995
Holden220191979
N. Andover220181995
Chilmark119751975
Marion120191972
Wellfleet120071971
Brockton120171984
Maynard120171990
Littleton120141967
N Oxford120071979
Mansfield120191994
Princeton119731973
Belchertown120211972
Warren120071968
S Barre120231973
N Orange120191976
Cummington120121969
Cheshire119881976
Pittsfield120091970

Black-billed Cuckoo Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.