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

Vesper Sparrow Population Trend in California

All statesGrassland birds

Vesper Sparrow in California has surged: up 638% on the route-weighted index since 1972.

+638%Since 1972
41Routes In State
54Years

Notable Vesper Sparrow Trends in California

long arc increasecomputed index

Vesper Sparrow has surged in California: up 638% on the route-weighted index since 1972.

Vesper Sparrow Population Forecast in California

If the recent trend holds, Vesper Sparrow in California is projected to rise about 35% by 2029 — from 0.84 in 2024 to a central estimate of 1.1 (95% range 0.28–2.0). A 5-year backtest shows a typical error of ±119.7%, with 60% of held-out values landing inside the 95% band.

+35%Change by 2029
1.1Projected 2029 index
0.28–2.095% range
±119.7%Backtest error
19702029
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
20251.10.272.0
20261.10.272.0
20271.10.272.0
20281.10.282.0
20291.10.282.0

Vesper Sparrow Survey Routes in California

Routes recording Vesper Sparrow in California.
Macdoel2320191973
Clear Lk Res2020181972
Ravendale1920241978
Goumaz1820111997
Bridgeport1719731973
Last Chance1720191993
Crowder Flat1520192002
Sattley1520241972
Crowley Lake1220241973
Bodie1220241982
Coalinga1019861986
Madeline920241997
Little Truckee920231997
Davis Creek820241972
Tionesta620211997
Tres Pinos519731973
Hackamore420102000
Mt Shasta420051972
Honey Lake220231976
Dorris220181974
Orleans219721972
Crestview220241999
Big Bear219861971
Ingalls220001973
Lakeshore220062006

Vesper Sparrow Population Trend in Other States

arizonacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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