BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Trumpeter Swan In Northern Rockies

All regionsNorthern RockiesWaterfowl

Trumpeter Swan in Northern Rockies has collapsed: down 84% on the route-weighted index since 1975.

-84%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 →
43YearsYears 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 2029 — from 0.19 in 2024 to a central estimate of 0.00 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±181.3%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.6495% 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 →
±181.3%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 Northern Rockies is projected to fall about 100% by 2029 — from 0.19 in 2024 to a central estimate of 0.00 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±181.3%, with 100% of held-out values landing inside the 95% band.19732029
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 →
20250.000.000.64
20260.000.000.64
20270.000.000.64
20280.000.000.64
20290.000.000.64

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 →
FontenelleWYOMING172024
NaplesIDAHO82021
BeaverheadMONTANA42023
KalispellMONTANA22013
Red RockMONTANA22024
Inside RoadMONTANA22024
MammothWYOMING22024
AlpineWYOMING21998
RyegrassWYOMING22016
SeedskadeeWYOMING22016
Seedskadee 2WYOMING22024
AugustaMONTANA12021
Pablo Res.MONTANA12024
Clover CreekOREGON11996
RandolphUTAH12023
Ne EntranceWYOMING12018
Hunter PeakWYOMING12002
MooseWYOMING12021
BoulderWYOMING12023
Mtn ViewWYOMING12024
MoranWYOMING12016
YellowstoneWYOMING12021

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