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Species · BCR 19 · BBS 2025 Release · 1966–2024

Trumpeter Swan In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieWaterfowl

Trumpeter Swan in Central Mixed Grass Prairie has declined: down 37% on the route-weighted index since 1994.

-37%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 →
6Routes 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 →
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 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 Trumpeter Swan in Central Mixed Grass Prairie. See the full index history below.

Trumpeter Swan In Central Mixed Grass Prairie Population Forecast

If the recent trend holds, Trumpeter Swan in Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 0.06 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±130.3%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.06Projected 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 →
0.00–0.1195% 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 →
±130.3%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 Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 0.06 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±130.3%, with 100% of held-out values landing inside the 95% band.19832029
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 →
20250.060.000.11
20260.060.000.11
20270.060.000.11
20280.060.000.11
20290.060.000.11

Routes In Central Mixed Grass Prairie

Routes recording Trumpeter Swan in Central Mixed Grass 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 →
GordonNEBRASKA32005
Piester LakeNEBRASKA22024
MullenNEBRASKA22023
Swan LakeNEBRASKA12015
BrownleeNEBRASKA12017
NenzelNEBRASKA12022

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