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

Violet-green Swallow In Coastal California

All regionsCoastal CaliforniaAerial insectivores

Violet-green Swallow in Coastal California has fallen sharply: down 60% on the route-weighted index since 1970.

-60%Since 1970
94Routes In Region
56Years

Notable Signals

long arc declinecomputed index

Violet-green Swallow has fallen sharply in Coastal California: down 60% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Violet-green Swallow in Coastal California is projected to fall about 28% by 2029 — from 5.0 in 2024 to a central estimate of 3.6 (95% range 0.00–7.3). A 5-year backtest shows a typical error of ±32.9%, with 100% of held-out values landing inside the 95% band.

-28%Change by 2029
3.6Projected 2029 index
0.00–7.395% range
±32.9%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
20254.20.458.0
20264.00.307.8
20273.90.157.6
20283.70.007.5
20293.60.007.3

Routes In Coastal California

Routes recording Violet-green Swallow in Coastal California.
ArvinCALIFORNIA1721988
Big BearCALIFORNIA821986
Lake HemetCALIFORNIA631986
RiovistaCALIFORNIA572022
FairfaxCALIFORNIA472024
Carmel ValCALIFORNIA412024
ValyermoCALIFORNIA412019
Tres Pinos 2CALIFORNIA392011
FallsvaleCALIFORNIA331981
White RiverCALIFORNIA241992
Point ReyesCALIFORNIA232023
GlennCALIFORNIA221991
Glen EllenCALIFORNIA222004
LockwoodCALIFORNIA202024
AdelaidaCALIFORNIA182024
FolsomCALIFORNIA172024
Cal Hot SpgsCALIFORNIA162019
Santa YnezCALIFORNIA152019
CoyoteCALIFORNIA132024
AuburnCALIFORNIA111980
AthloneCALIFORNIA111980
PescaderoCALIFORNIA112024
Mt PinosCALIFORNIA102004
Mesa GrandeCALIFORNIA102024
GreenfieldCALIFORNIA102024

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