BirdAnalyst
Species · Wisconsin · BBS 2026 Release · 1966–2025

Trumpeter Swan Population Trend in Wisconsin

All statesWaterfowl

Trumpeter Swan in Wisconsin has surged: up 647% on the route-weighted index since 1995.

+647%Since 1995TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
23YearsYears 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 WisconsinNotable 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 Wisconsin: up 647% on the route-weighted index since 1995.

Trumpeter Swan Population Forecast in Wisconsin

If the recent trend holds, Trumpeter Swan in Wisconsin is projected to stay roughly flat through 2030, near 0.40 (95% range 0.15–0.65). A 5-year backtest shows a typical error of ±56%, with 20% of held-out values landing inside the 95% band.

+5%Change by 2030TrendPercent 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 →
0.40Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.15–0.6595% 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 →
±56%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 Wisconsin is projected to stay roughly flat through 2030, near 0.40 (95% range 0.15–0.65). A 5-year backtest shows a typical error of ±56%, with 20% of held-out values landing inside the 95% band.19932030
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 →
20260.350.100.60
20270.360.120.61
20280.380.130.62
20290.390.140.64
20300.400.150.65

Trumpeter Swan Survey Routes in Wisconsin

Routes recording Trumpeter Swan in Wisconsin.
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 →
Hudson1320252007
Esdaile1020222022
Brownsville820222022
Dresser720242012
Bashaw720252021
Cavour520222022
Mather420231994
Buena Vista420242024
Minong320032003
Loraine320251995
Flambeau320172013
Iron River220252025
Grand View220252014
Shanagolden220212009
Cumberland220242011
Weyerhauser220232023
Gilman220252013
Princeton220242024
N Andover220222022
Land O Lakes120142011
Union Twp120232007
Couderay120152015
Pigeon Creek120242022
Cochrane120222022
Unity120172017

Trumpeter Swan Population Trend in Other States

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Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.