BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Black-billed Cuckoo In Northern Rockies

All regionsNorthern RockiesGeneralists

Black-billed Cuckoo in Northern Rockies has collapsed: down 92% on the route-weighted index since 1972.

-92%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 →
14Routes 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 →
22YearsYears 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 Northern Rockies: down 92% on the route-weighted index since 1972.

Black-billed Cuckoo In Northern Rockies Population Forecast

If the recent trend holds, Black-billed Cuckoo in Northern Rockies is projected to stay roughly flat through 2022, near 0.00 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±1124.6%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2022TrendPercent 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 2022 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2195% 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 →
±1124.6%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 Northern Rockies is projected to stay roughly flat through 2022, near 0.00 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±1124.6%, with 100% of held-out values landing inside the 95% band.19682022
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 →
20180.000.000.21
20190.000.000.21
20200.000.000.21
20210.000.000.21
20220.000.000.21

Routes In Northern Rockies

Routes recording Black-billed Cuckoo in Northern Rockies.
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 →
OttoWYOMING41981
Willow Creek 2MONTANA22014
BasinWYOMING21985
RiversideWYOMING21969
ClarkWYOMING22017
CentervilleIDAHO11984
St MaryMONTANA11989
AugustaMONTANA11981
Twin BridgesMONTANA11976
Willow CreekMONTANA11978
ChestnutMONTANA11989
LaurelMONTANA11997
St. Mary 2MONTANA12012
MooseWYOMING11982

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