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

Savannah Sparrow Population Trend in California

All statesGrassland birds

Savannah Sparrow in California has risen sharply: up 65% on the route-weighted index since 1970.

+65%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 →
77Routes 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 Savannah 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Savannah Sparrow has risen sharply in California: up 65% on the route-weighted index since 1970.

Savannah Sparrow Population Forecast in California

If the recent trend holds, Savannah Sparrow in California is projected to rise about 77% by 2029 — from 0.71 in 2024 to a central estimate of 1.3 (95% range 0.25–2.3). A 5-year backtest shows a typical error of ±276.6%, with 40% of held-out values landing inside the 95% band.

+77%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 →
1.3Projected 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 →
0.25–2.395% 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 →
±276.6%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, Savannah Sparrow in California is projected to rise about 77% by 2029 — from 0.71 in 2024 to a central estimate of 1.3 (95% range 0.25–2.3). A 5-year backtest shows a typical error of ±276.6%, with 40% 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 →
20251.20.232.3
20261.20.242.3
20271.30.242.3
20281.30.242.3
20291.30.252.3

Savannah Sparrow Survey Routes in California

Routes recording Savannah 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 →
Poway3819801973
Dorris3820191972
Hughson3019771977
Crowley Lake2520241972
Likely1520241972
Macdoel1320191972
Clear Lk Res1220181977
Rio Dell1020121972
Orland1019931993
Ravendale920241974
Oilfields820051973
Yreka820191973
Goumaz820111997
Honeydew720171968
Ingalls620001973
Sattley620241972
Riovista520232008
Ora Loma519761976
Nubieber420181970
Crescent Cty420241975
San Ysidro419761973
Bodega Bay420191973
Collegeville319721972
Fairfax319731973
Carrizo Pln320231993

Savannah Sparrow Population Trend in Other States

alaskaarizonacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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