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

Cassin's Vireo In Coastal California

All regionsCoastal CaliforniaForest birds

Cassin's Vireo in Coastal California has surged: up 155% on the route-weighted index since 1970.

+155%Since 1970
60Routes In Region
56Years

Notable Signals

long arc increasecomputed index

Cassin's Vireo has surged in Coastal California: up 155% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Cassin's Vireo in Coastal California is projected to rise about 170% by 2029 — from 0.34 in 2024 to a central estimate of 0.92 (95% range 0.37–1.5). A 5-year backtest shows a typical error of ±125.7%, with 40% of held-out values landing inside the 95% band.

+170%Change by 2029
0.92Projected 2029 index
0.37–1.595% range
±125.7%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
20250.890.341.4
20260.900.351.4
20270.910.361.5
20280.910.361.5
20290.920.371.5

Routes In Coastal California

Routes recording Cassin's Vireo in Coastal California.
StonyfordCALIFORNIA202018
Bartlett SpsCALIFORNIA132018
Hough SpringsCALIFORNIA132007
CalpellaCALIFORNIA81986
CohassetCALIFORNIA72024
Glen EllenCALIFORNIA62004
Glen Ellen 2CALIFORNIA62023
SisquocCALIFORNIA42000
TehamaCALIFORNIA42022
MoragaCALIFORNIA42011
Waterman GapCALIFORNIA42024
White RiverCALIFORNIA31991
Gold HillCALIFORNIA32017
Mark WestCALIFORNIA32019
TomheadCALIFORNIA32011
Santa YnezCALIFORNIA22014
JacksonCALIFORNIA21992
Lake Hemet 2CALIFORNIA22023
Angelus OaksCALIFORNIA22017
PolomaCALIFORNIA22016
AlamarCALIFORNIA22003
Red BluffCALIFORNIA12022
RumseyCALIFORNIA12007
Yokohl ValCALIFORNIA11993
Foster ParkCALIFORNIA11986

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