BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

White-throated Swift In Coastal California

All regionsCoastal CaliforniaAerial insectivores

White-throated Swift in Coastal California has fallen sharply: down 72% on the route-weighted index since 1970.

-72%Since 1970
75Routes In Region
56Years

Notable Signals

long arc declinecomputed index

White-throated Swift has fallen sharply in Coastal California: down 72% on the route-weighted index since 1970.

Forecast

If the recent trend holds, White-throated Swift in Coastal California is projected to fall about 62% by 2029 — from 1.4 in 2024 to a central estimate of 0.54 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±58%, with 100% of held-out values landing inside the 95% band.

-62%Change by 2029
0.54Projected 2029 index
0.00–2.595% range
±58%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
20250.640.002.6
20260.610.002.5
20270.590.002.5
20280.560.002.5
20290.540.002.5

Routes In Coastal California

Routes recording White-throated Swift in Coastal California.
Angelus OaksCALIFORNIA262017
Santa YnezCALIFORNIA202019
El ToroCALIFORNIA151999
CoyoteCALIFORNIA152024
CopperopolisCALIFORNIA132024
San YsidroCALIFORNIA102019
Lake SuccessCALIFORNIA101980
FallsvaleCALIFORNIA91981
Elizabeth LkCALIFORNIA92015
RiovistaCALIFORNIA82019
Green ValleyCALIFORNIA82022
WestleyCALIFORNIA82019
Sawmill MtnCALIFORNIA72022
Lake HemetCALIFORNIA71974
CrestonCALIFORNIA72024
San Benito Mtn.CALIFORNIA72009
Lake CachumaCALIFORNIA62016
Harbor Lake 2CALIFORNIA62024
CoalingaCALIFORNIA52002
PowayCALIFORNIA51980
Mesa GrandeCALIFORNIA52017
Mt Pinos 2CALIFORNIA52024
GreenfieldCALIFORNIA52024
Tres Pinos 2CALIFORNIA52010
Red BluffCALIFORNIA42024

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