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Species · California · BBS 2025 Release · 1966–2024

Cassin's Kingbird Population Trend in California

All statesAerial insectivores

Cassin's Kingbird in California has surged: up 223% on the route-weighted index since 1971.

+223%Since 1971
49Routes In State
55Years

Notable Cassin's Kingbird Trends in California

long arc increasecomputed index

Cassin's Kingbird has surged in California: up 223% on the route-weighted index since 1971.

Cassin's Kingbird Population Forecast in California

If the recent trend holds, Cassin's Kingbird in California is projected to fall about 66% by 2029 — from 1.1 in 2024 to a central estimate of 0.37 (95% range 0.02–0.71). A 5-year backtest shows a typical error of ±60.4%, with 40% of held-out values landing inside the 95% band.

-66%Change by 2029
0.37Projected 2029 index
0.02–0.7195% range
±60.4%Backtest error
19692029
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
20250.350.000.69
20260.350.010.70
20270.360.010.70
20280.360.020.71
20290.370.020.71

Cassin's Kingbird Survey Routes in California

Routes recording Cassin's Kingbird in California.
Moreno2620241982
Oak Grove1820241969
Jofegan 21720242024
Elsinore Mtn1120241995
Hollister 21120242016
San Ysidro1020191986
Elizabeth Lk920161979
Creston819831982
Imperial Dam820061976
Lenwood719801980
Santa Ynez620191969
Harbor Lake 2620242014
Anza619811972
Cp. Pendleton520041972
Jacumba420241973
Foster Park419811970
Mt Pinos419691969
Cima419981975
Sisquoc420141981
Cottonwood319891989
Woodlands320162012
Green Valley220162013
Tres Pinos219771977
Lockwood220041972
Jofegan220232006

Cassin's Kingbird Population Trend in Other States

arizonacoloradokansasmontananebraskanevadanew-mexicooklahomasouth-dakotatexasutahwyoming

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