BirdAnalyst
Species · BCR 14 · BBS 2025 Release · 1966–2024

Black-billed Cuckoo In Atlantic Northern Forest

All regionsAtlantic Northern ForestGeneralists

Black-billed Cuckoo in Atlantic Northern Forest has collapsed: down 76% on the route-weighted index since 1968.

-76%Since 1968TrendPercent 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 →
129Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Atlantic Northern Forest: down 76% on the route-weighted index since 1968.

Black-billed Cuckoo In Atlantic Northern Forest Population Forecast

If the recent trend holds, Black-billed Cuckoo in Atlantic Northern Forest is projected to fall about 100% by 2029 — from 0.14 in 2024 to a central estimate of 0.00 (95% range 0.00–0.55). A 5-year backtest shows a typical error of ±92.4%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2029TrendPercent 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 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.5595% 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 →
±92.4%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 Atlantic Northern Forest is projected to fall about 100% by 2029 — from 0.14 in 2024 to a central estimate of 0.00 (95% range 0.00–0.55). A 5-year backtest shows a typical error of ±92.4%, 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 →
20250.000.000.55
20260.000.000.55
20270.000.000.55
20280.000.000.55
20290.000.000.55

Routes In Atlantic Northern Forest

Routes recording Black-billed Cuckoo in Atlantic Northern Forest.
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 →
SpeculatorNEW-YORK51973
EastbrookMAINE41987
WaiteMAINE41977
BentonMAINE31980
DebloisMAINE32007
WytopitlockMAINE31979
HighmarketNEW-YORK32006
SciotaNEW-YORK31978
New HartfordCONNECTICUT22019
BiddefordMAINE22004
TurnerMAINE22002
WarrenMAINE21988
CooperMAINE22004
CharlestonMAINE21995
MedwayMAINE21979
LudlowMAINE21995
WashburnMAINE21996
Heron LakeMAINE21994
ChesterfieldMASSACHUSETTS22018
PeterboroughNEW-HAMPSHIRE21996
KasoagNEW-YORK22015
Blue Ridge SNEW-YORK21991
North RiverNEW-YORK21995
St Regis FlsNEW-YORK22007
S ReadingVERMONT21986

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