BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

American Wigeon In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauWaterfowl

American Wigeon in Southern Rockies / Colorado Plateau has fallen sharply: down 55% on the route-weighted index since 1977.

-55%Since 1977TrendPercent 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 →
29Routes 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 →
44YearsYears 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 Southern Rockies / Colorado Plateau: down 55% on the route-weighted index since 1977.

American Wigeon In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, American Wigeon in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 0.18 (95% range 0.00–0.50). A 5-year backtest shows a typical error of ±801.3%, 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 →
0.18Projected 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 →
0.00–0.5095% 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 →
±801.3%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 Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 0.18 (95% range 0.00–0.50). A 5-year backtest shows a typical error of ±801.3%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.180.000.50
20260.180.000.50
20270.180.000.50
20280.180.000.50
20290.180.000.50

Routes In Southern Rockies / Colorado Plateau

Routes recording American Wigeon in Southern Rockies / Colorado Plateau.
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 →
VernalUTAH142012
WaldenCOLORADO52015
M Warner ResUTAH52022
CortezCOLORADO42006
BrookhurstWYOMING42009
Sybille CynWYOMING32024
GuffeyCOLORADO22018
AlamosaCOLORADO22008
PiedraCOLORADO22014
DinosaurCOLORADO22021
Mcphee Res.COLORADO22004
Yellowjacket PassCOLORADO22023
Cochetopa PassCOLORADO22015
CapulinNEW-MEXICO21993
Skyline DrivUTAH22007
Ant Flat-Ogden CanUTAH22019
Beck 2UTAH22005
BufordWYOMING21998
MoffatCOLORADO11976
Rio Grnds RsCOLORADO12022
TincupCOLORADO12018
Lake City 2COLORADO12022
Stillwater PassCOLORADO12006
DulceNEW-MEXICO12011
Angel Fire 2NEW-MEXICO12017

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