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

Common Goldeneye In Northern Rockies

All regionsNorthern RockiesWaterfowl

Common Goldeneye in Northern Rockies has fallen sharply: down 72% on the route-weighted index since 1980.

-72%Since 1980TrendPercent 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 →
23Routes 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 →
38YearsYears 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 →

Common Goldeneye has fallen sharply in Northern Rockies: down 72% on the route-weighted index since 1980.

Common Goldeneye In Northern Rockies Population Forecast

If the recent trend holds, Common Goldeneye in Northern Rockies is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±42.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.02Projected 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 →
0.00–0.1095% 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 →
±42.1%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, Common Goldeneye in Northern Rockies is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±42.1%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.030.000.11
20260.030.000.11
20270.030.000.10
20280.030.000.10
20290.020.000.10

Routes In Northern Rockies

Routes recording Common Goldeneye 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 →
YellowstoneWYOMING101999
WilsonWYOMING61980
MooseWYOMING31992
Fiddler LkWYOMING31980
NaplesIDAHO22024
KalispellMONTANA22014
St MaryMONTANA22000
EllistonMONTANA22014
BeaverheadMONTANA21974
Whitefish LakeMONTANA22023
LaurierWASHINGTON22022
L Pend O NwrWASHINGTON22021
DuboisWYOMING22009
CoolinIDAHO11998
ArleeMONTANA12013
AugustaMONTANA12015
NoxonMONTANA12018
East Glacier ParkMONTANA12015
Twin LakesWASHINGTON11985
CusickWASHINGTON12017
CurlewWASHINGTON12018
FontenelleWYOMING12022
BoulderWYOMING11999

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