BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Trumpeter Swan In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWaterfowl

Trumpeter Swan in Prairie Hardwood Transition has surged: up 42× on the route-weighted index since 1994.

42×Since 1994TrendPercent 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 →
35Routes 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 →
29YearsYears 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 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 Prairie Hardwood Transition: up 42× on the route-weighted index since 1994.

Trumpeter Swan In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Trumpeter Swan in Prairie Hardwood Transition is projected to fall about 23% by 2029 — from 0.65 in 2024 to a central estimate of 0.49 (95% range 0.32–0.68). A 5-year backtest shows a typical error of ±33.5%, with 40% of held-out values landing inside the 95% band.

-23%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 →
0.49Projected 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 →
0.32–0.6895% 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 →
±33.5%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 Prairie Hardwood Transition is projected to fall about 23% by 2029 — from 0.65 in 2024 to a central estimate of 0.49 (95% range 0.32–0.68). A 5-year backtest shows a typical error of ±33.5%, with 40% of held-out values landing inside the 95% band.19902029
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 →
20250.440.260.62
20260.450.270.63
20270.470.290.65
20280.480.300.66
20290.490.320.68

Routes In Prairie Hardwood Transition

Routes recording Trumpeter Swan in Prairie Hardwood Transition.
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 →
Sherburne NrMINNESOTA192024
LoraineWISCONSIN142021
HudsonWISCONSIN132024
BrownsvilleWISCONSIN82022
DresserWISCONSIN72024
KnappMINNESOTA42024
EdwardsMINNESOTA42024
MatherWISCONSIN42023
Buena VistaWISCONSIN42024
CohoctahMICHIGAN32024
LimestoneOHIO32019
Money CreekMINNESOTA22024
MinnetonkaMINNESOTA22024
PrincetonMINNESOTA22024
Le CenterMINNESOTA22015
Brook ParkMINNESOTA22018
AshbyMINNESOTA22021
CumberlandWISCONSIN22024
WeyerhauserWISCONSIN22023
PrincetonWISCONSIN22024
N AndoverWISCONSIN22022
LawrenceMICHIGAN12023
NashvilleMICHIGAN12006
GalesburgMICHIGAN12019
HowardsvilleMICHIGAN12015

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