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

Lark Sparrow Population Trend in California

All statesGrassland birds

Lark Sparrow in California has declined: down 50% on the route-weighted index since 1970.

-50%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
175Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lark Sparrow Trends in CaliforniaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Lark Sparrow in California. See the full index history below.

Lark Sparrow Population Forecast in California

If the recent trend holds, Lark Sparrow in California is projected to stay roughly flat through 2029, near 1.4 (95% range 0.25–2.6). A 5-year backtest shows a typical error of ±27.6%, with 100% of held-out values landing inside the 95% band.

-2%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
1.4Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.25–2.695% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±27.6%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Lark Sparrow in California is projected to stay roughly flat through 2029, near 1.4 (95% range 0.25–2.6). A 5-year backtest shows a typical error of ±27.6%, with 100% of held-out values landing inside the 95% band.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 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20251.50.352.7
20261.50.332.7
20271.50.302.7
20281.50.282.7
20291.40.252.6

Lark Sparrow Survey Routes in California

Routes recording Lark Sparrow in California.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Ventucopa4120021972
White River3419921972
Ingalls2219991973
Yokohl Val2119971972
Red Bluff1920241968
Yolla Bolly1820241973
Onyx1620151968
Shafter1119891973
Mt Laguna1019871970
Ono920121984
Maricopa920241970
Honey Lake920231972
Alderpoint920121974
Sanger820242011
Jackson819921973
Tres Pinos 2820112008
Lumberyard719881988
Lone Pine719981972
Greenwater V719981975
Cordova719791974
Sattley720121981
Macdoel720191972
Tionesta720212003
Tomhead720111998
Coalinga620221973

Lark Sparrow Population Trend in Other States

alabamaarizonaarkansascoloradoidahoillinoisindianaiowakansaskentuckylouisianaminnesotamississippimissourimontananebraskanevadanew-mexiconorth-dakotaohiooklahomaoregonsouth-dakotatennesseetexasutahwashingtonwisconsinwyoming

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