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Species · Wyoming · BBS 2025 Release · 1966–2024

Bufflehead Population Trend in Wyoming

All statesWaterfowl

Bufflehead in Wyoming has fallen sharply: down 56% on the route-weighted index since 1989.

-56%Since 1989TrendPercent 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 →
9Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
35YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bufflehead Trends in WyomingNotable 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 →

Bufflehead has fallen sharply in Wyoming: down 56% on the route-weighted index since 1989.

Bufflehead Population Forecast in Wyoming

If the recent trend holds, Bufflehead in Wyoming is projected to stay roughly flat through 2028, near 0.04 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±171.7%, 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 →
0.04Projected 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 →
0.00–0.2795% 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 →
±171.7%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, Bufflehead in Wyoming is projected to stay roughly flat through 2028, near 0.04 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±171.7%, with 100% of held-out values landing inside the 95% band.19852028
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 →
20240.070.000.29
20250.060.000.29
20260.050.000.28
20270.040.000.27
20280.040.000.27

Bufflehead Survey Routes in Wyoming

Routes recording Bufflehead in Wyoming.
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 →
Yellowstone920221988
Hayden Val719851985
Mammoth220061996
Hunter Peak120062006
Ne Entrance119991999
Walcott120171992
Fiddler Lk120052002
Bucknum119991999
Colter Bay 2120232023

Bufflehead Population Trend in Other States

alaskacaliforniacoloradoidahominnesotamontananevadanorth-dakotaoregonsouth-dakotautahwashingtonwisconsin

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