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

Vaux's Swift In Northern Rockies

All regionsNorthern RockiesAerial insectivores

Vaux's Swift in Northern Rockies has fallen sharply: down 61% on the route-weighted index since 1974.

-61%Since 1974TrendPercent 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 →
70Routes 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 →
53YearsYears 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 →

Vaux's Swift has fallen sharply in Northern Rockies: down 61% on the route-weighted index since 1974.

Vaux's Swift In Northern Rockies Population Forecast

If the recent trend holds, Vaux's Swift in Northern Rockies is projected to rise about 58% by 2030 — from 0.10 in 2025 to a central estimate of 0.16 (95% range 0.00–0.49). A 5-year backtest shows a typical error of ±158.4%, with 100% of held-out values landing inside the 95% band.

+58%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 →
0.16Projected 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 →
0.00–0.4995% 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 →
±158.4%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, Vaux's Swift in Northern Rockies is projected to rise about 58% by 2030 — from 0.10 in 2025 to a central estimate of 0.16 (95% range 0.00–0.49). A 5-year backtest shows a typical error of ±158.4%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20260.180.000.51
20270.170.000.50
20280.170.000.50
20290.170.000.50
20300.160.000.49

Routes In Northern Rockies

Routes recording Vaux's Swift 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 →
Inside RoadMONTANA202012
Baldy MountainIDAHO122015
TwickenhamOREGON102012
CentervilleIDAHO82008
Eagle RockOREGON81971
BridgeportOREGON71999
GrangevilleIDAHO62007
Rochat DivdeIDAHO62025
WickiupOREGON62022
UnityOREGON62004
CoolinIDAHO52024
Pablo Res.MONTANA52010
OchocoOREGON52022
DonnellyOREGON52005
Twin LakesWASHINGTON51990
St RegisMONTANA42023
OchocoOREGON41982
TroyOREGON42024
Black Mtn.OREGON42004
Eagle CreekOREGON42022
CusickWASHINGTON42024
WoodmanMONTANA31997
Logan PassMONTANA32023
SpartaOREGON32001
Mount VernonOREGON32018

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