BirdAnalyst
Species · Wyoming · BBS 2025 Release · 1966–2024

Trumpeter Swan Population Trend in Wyoming

All statesWaterfowl

Trumpeter Swan in Wyoming has surged: up 441% on the route-weighted index since 1992.

+441%Since 1992TrendPercent 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 →
13Routes 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 →
32YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Trumpeter Swan 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 increasecomputed 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 →

Trumpeter Swan has surged in Wyoming: up 441% on the route-weighted index since 1992.

Trumpeter Swan Population Forecast in Wyoming

If the recent trend holds, Trumpeter Swan in Wyoming is projected to stay roughly flat through 2029, near 0.24 (95% range 0.09–0.39). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.

-4%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 →
0.24Projected 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 →
0.09–0.3995% 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 →
±18.7%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, Trumpeter Swan in Wyoming is projected to stay roughly flat through 2029, near 0.24 (95% range 0.09–0.39). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.19882029
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 →
20250.210.070.36
20260.220.070.37
20270.230.080.37
20280.230.080.38
20290.240.090.39

Trumpeter Swan Survey Routes in Wyoming

Routes recording Trumpeter Swan 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 →
Fontenelle1720242011
Seedskadee220161997
Seedskadee 2220242024
Ryegrass220162016
Alpine219981995
Mammoth220242004
Hunter Peak120022002
Ne Entrance120181988
Moose120211998
Yellowstone120211988
Boulder120231998
Moran120162016
Mtn View120242024

Trumpeter Swan Population Trend in Other States

alaskaarkansasidahoiowamichiganminnesotamontananebraskanevadanorth-dakotaohiooregonsouth-dakotautahwashingtonwisconsin

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