BirdAnalyst
Species · BCR 18 · BBS 2025 Release · 1966–2024

American Wigeon In Shortgrass Prairie

All regionsShortgrass PrairieWaterfowl

American Wigeon in Shortgrass Prairie has fallen sharply: down 50% on the route-weighted index since 1986.

-50%Since 1986TrendPercent 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 →
18Routes 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 →
19YearsYears 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 Shortgrass Prairie. See the full index history below.

American Wigeon In Shortgrass Prairie Population Forecast

If the recent trend holds, American Wigeon in Shortgrass Prairie is projected to stay roughly flat through 2028, near 0.03 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±121.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.03Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1195% 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 →
±121.7%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 Shortgrass Prairie is projected to stay roughly flat through 2028, near 0.03 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±121.7%, with 100% of held-out values landing inside the 95% band.19732028
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 →
20240.040.000.11
20250.040.000.11
20260.040.000.11
20270.030.000.11
20280.030.000.11

Routes In Shortgrass Prairie

Routes recording American Wigeon in Shortgrass Prairie.
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 →
MaxwellNEW-MEXICO102006
GroverCOLORADO42008
HaswellCOLORADO41996
JulesburgCOLORADO42012
Wildhorse LCOLORADO31999
KiowaCOLORADO22012
Last ChanceCOLORADO22005
AmherstCOLORADO22009
NunnCOLORADO22017
Arsenal 2COLORADO22022
PaxtonNEBRASKA22008
ChanningTEXAS21980
PinneoCOLORADO11973
LamarCOLORADO12023
Murray LakeNEBRASKA11988
Cooley LakeNEW-MEXICO12023
WakaTEXAS11980
YoderWYOMING11986

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