BirdAnalyst
Species · BCR 10 · BBS 2026 Release · 1966–2025

American Wigeon In Northern Rockies

All regionsNorthern RockiesWaterfowl

American Wigeon in Northern Rockies has fallen sharply: down 57% on the route-weighted index since 1974.

-57%Since 1974TrendPercent 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 →
79Routes 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 →
52YearsYears 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 →

American Wigeon has fallen sharply in Northern Rockies: down 57% on the route-weighted index since 1974.

American Wigeon In Northern Rockies Population Forecast

If the recent trend holds, American Wigeon in Northern Rockies is projected to rise about 84% by 2030 — from 0.28 in 2025 to a central estimate of 0.51 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±116.6%, with 100% of held-out values landing inside the 95% band.

+84%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 →
0.51Projected 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 →
0.00–1.295% 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 →
±116.6%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, American Wigeon in Northern Rockies is projected to rise about 84% by 2030 — from 0.28 in 2025 to a central estimate of 0.51 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±116.6%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20260.520.001.2
20270.520.001.2
20280.520.001.2
20290.510.001.2
20300.510.001.2

Routes In Northern Rockies

Routes recording American Wigeon 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 →
Saleratus CrUTAH162018
Hayden ValWYOMING131986
NowoodWYOMING122025
RandolphUTAH82021
YellowstoneWYOMING82025
Crane CreekIDAHO62002
NaplesIDAHO52025
Salmon RiverIDAHO51998
Clover CreekOREGON51989
SeedskadeeWYOMING52016
PolsonMONTANA42000
GlenMONTANA42017
Neponset ResUTAH42018
ErvayWYOMING42022
RawlinsWYOMING42006
WalcottWYOMING42025
East Glacier ParkMONTANA32022
PhilipsburgMONTANA32025
ChewelahWASHINGTON31990
L Pend O NwrWASHINGTON32016
Elk HornWYOMING32015
ClarkWYOMING31992
DanielWYOMING31988
ShirleyWYOMING32024
BaggsWYOMING31998

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