BirdAnalyst
Species · California · BBS 2025 Release · 1966–2024

Vaux's Swift Population Trend in California

All statesAerial insectivores

Vaux's Swift in California has declined: down 37% on the route-weighted index since 1971.

-37%Since 1971
60Routes In State
54Years

Notable Vaux's Swift Trends in California

No notable trend signals for Vaux's Swift in California. See the full index history below.

Vaux's Swift Population Forecast in California

If the recent trend holds, Vaux's Swift in California is projected to rise about 124% by 2029 — from 0.09 in 2024 to a central estimate of 0.19 (95% range 0.01–0.38). A 5-year backtest shows a typical error of ±206%, with 60% of held-out values landing inside the 95% band.

+124%Change by 2029
0.19Projected 2029 index
0.01–0.3895% range
±206%Backtest error
19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20250.200.010.38
20260.200.010.38
20270.190.010.38
20280.190.010.38
20290.190.010.38

Vaux's Swift Survey Routes in California

Routes recording Vaux's Swift in California.
Redwood N.P. 22220132012
Anza Borrego1219901990
Martins Fy720081976
Adelaida719771977
Orange Cove620021994
Strawberry619991999
Coyote520222012
Lakeshore520032003
Red Bluff420111994
Iron Gate420191989
Dorris420152011
Butte Meadow419971973
Lake Success419781977
Copperopolis420172017
Horse Creek320171972
Nubieber319971997
Hat Creek320021973
Rio Dell320061974
Crescent Cty220241972
Redwood N.P.220071995
Bass Lake220112006
Tuolumne Grove220242006
Fall River Mills220111998
Longvale220171998
Orleans220041983

Vaux's Swift Population Trend in Other States

alaskaidahomontanaoregonwashington

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