BirdAnalyst
Species · BCR 10 · BBS 2026 Release · 1966–2025

Trumpeter Swan In Northern Rockies

All regionsNorthern RockiesWaterfowl

Trumpeter Swan in Northern Rockies has collapsed: down 83% on the route-weighted index since 1975.

-83%Since 1975TrendPercent 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 →
22Routes 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 →
44YearsYears 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 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 →

Trumpeter Swan has collapsed in Northern Rockies: down 83% on the route-weighted index since 1975.

Trumpeter Swan In Northern Rockies Population Forecast

If the recent trend holds, Trumpeter Swan in Northern Rockies is projected to fall about 100% by 2030 — from 0.19 in 2025 to a central estimate of 0.00 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±176.9%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.6495% 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 →
±176.9%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 Northern Rockies is projected to fall about 100% by 2030 — from 0.19 in 2025 to a central estimate of 0.00 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±176.9%, with 100% of held-out values landing inside the 95% band.19732030
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 →
20260.000.000.64
20270.000.000.64
20280.000.000.64
20290.000.000.64
20300.000.000.64

Routes In Northern Rockies

Routes recording Trumpeter Swan in Northern Rockies.
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 →
Red RockMONTANA142025
NaplesIDAHO82021
FontenelleWYOMING52025
BeaverheadMONTANA42023
Pablo Res.MONTANA42025
Inside RoadMONTANA22024
MammothWYOMING22025
AlpineWYOMING21998
Mtn ViewWYOMING22025
RyegrassWYOMING22016
SeedskadeeWYOMING22016
Seedskadee 2WYOMING22024
KalispellMONTANA12025
AugustaMONTANA12021
Clover CreekOREGON11996
RandolphUTAH12025
Ne EntranceWYOMING12018
Hunter PeakWYOMING12002
MooseWYOMING12021
BoulderWYOMING12023
MoranWYOMING12016
YellowstoneWYOMING12021

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