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

Bell's Vireo Population Trend in California

All statesForest birds

Bell's Vireo in California has surged: up 725% on the route-weighted index since 1976.

+725%Since 1976
18Routes In State
30Years

Notable Bell's Vireo Trends in California

long arc increasecomputed index

Bell's Vireo has surged in California: up 725% on the route-weighted index since 1976.

Bell's Vireo Population Forecast in California

If the recent trend holds, Bell's Vireo in California is projected to fall about 36% by 2029 — from 0.18 in 2024 to a central estimate of 0.12 (95% range 0.03–0.20). A 5-year backtest shows a typical error of ±60%, with 60% of held-out values landing inside the 95% band.

-36%Change by 2029
0.12Projected 2029 index
0.03–0.2095% range
±60%Backtest error
19712029
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
20250.110.020.19
20260.110.020.20
20270.110.030.20
20280.110.030.20
20290.120.030.20

Bell's Vireo Survey Routes in California

Routes recording Bell's Vireo in California.
Jofegan 21620242024
San Ysidro520191992
Tecopa320231995
Cp. Pendleton220031975
Flynn119921992
Mesa Grande120102010
Creston119761976
Moreno120122012
Oak Grove120182010
Anza Borrego120241979
Jofegan120222015
Coalinga119761976
Orange Cove119971975
Atwater120122012
Cuyamaca Pk119711971
Poway119791979
Death Valley119961996
Wildrose120042004

Bell's Vireo Population Trend in Other States

arizonaarkansascoloradoillinoisindianaiowakansaskentuckymichiganminnesotamissourinebraskanevadanew-mexiconorth-dakotaohiooklahomasouth-dakotatexasutahwisconsin

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