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

American Wigeon In Northern Rockies

All regionsNorthern RockiesWaterfowl

American Wigeon in Northern Rockies has declined: down 46% on the route-weighted index since 1974.

-46%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 →
78Routes 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 →
51YearsYears 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 →

No notable trend signals for American Wigeon in Northern Rockies. See the full index history below.

American Wigeon In Northern Rockies Population Forecast

If the recent trend holds, American Wigeon in Northern Rockies is projected to rise about 168% by 2029 — from 0.20 in 2024 to a central estimate of 0.53 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±157%, with 100% of held-out values landing inside the 95% band.

+168%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 →
0.53Projected 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 →
0.00–1.295% 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 →
±157%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 168% by 2029 — from 0.20 in 2024 to a central estimate of 0.53 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±157%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20250.540.001.3
20260.540.001.2
20270.540.001.2
20280.540.001.2
20290.530.001.2

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
RandolphUTAH82021
NaplesIDAHO72024
Crane CreekIDAHO62002
YellowstoneWYOMING62022
Salmon RiverIDAHO51998
Clover CreekOREGON51989
SeedskadeeWYOMING52016
PolsonMONTANA42000
GlenMONTANA42017
Neponset ResUTAH42018
ErvayWYOMING42022
RawlinsWYOMING42006
East Glacier ParkMONTANA32022
RaynesfordMONTANA32024
ChewelahWASHINGTON31990
L Pend O NwrWASHINGTON32016
NowoodWYOMING32024
Elk HornWYOMING32015
ClarkWYOMING31992
DanielWYOMING31988
ShirleyWYOMING32024
BaggsWYOMING31998
MivodenIDAHO21980

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