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

Sora Population Trend in California

All statesWetland birds

Sora in California has surged: up 94% on the route-weighted index since 1975.

+94%Since 1975TrendPercent 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 →
22Routes 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 →
37YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Sora 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 Sora in California. See the full index history below.

Sora Population Forecast in California

If the recent trend holds, Sora in California is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±35.2%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.04Projected 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 →
0.00–0.0895% 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 →
±35.2%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, Sora in California is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±35.2%, with 100% of held-out values landing inside the 95% band.19732029
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 →
20250.030.000.07
20260.040.000.07
20270.040.000.07
20280.040.000.07
20290.040.000.08

Sora Survey Routes in California

Routes recording Sora 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 →
Imperial Dam519841983
Dorris420191982
Glenn319751973
Nubieber220172017
Likely220241976
Paxton220102008
Onyx219761976
Ora Loma219831983
Crescent Cty120242023
Dardanelle120172017
Hughson119961996
Westley119971997
Honey Lake119991995
Macdoel120191986
Tranquillity119731973
Harbor Lake119891989
Lockwood119841984
Cedarville120151975
Yreka120142014
Ingalls119921992
Ravendale119831983
Staten Is.120232023

Sora Population Trend in Other States

alaskaarizonacoloradoidahoillinoisindianaiowakansasmainemassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-dakotaohiooregonpennsylvaniasouth-dakotautahvermontwashingtonwisconsinwyoming

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