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

Common Gallinule Population Trend in California

All statesWetland birds

Common Gallinule in California has collapsed: down 82% on the route-weighted index since 1971.

-82%Since 1971TrendPercent 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 →
30Routes 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 →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Gallinule 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 declinecomputed 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 →

Common Gallinule has collapsed in California: down 82% on the route-weighted index since 1971.

Common Gallinule Population Forecast in California

If the recent trend holds, Common Gallinule in California is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±990%, 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 →
0.07Projected 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 →
0.00–0.2195% 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 →
±990%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, Common Gallinule in California is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±990%, with 100% of held-out values landing inside the 95% band.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 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 →
20250.070.000.21
20260.070.000.21
20270.070.000.21
20280.070.000.21
20290.070.000.21

Common Gallinule Survey Routes in California

Routes recording Common Gallinule 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 →
Glenn1220091971
Gravesboro419711969
Auburn319751975
Bakersfield219701970
Coyote219831976
Oneals219791979
Blythe219771977
Alamo River219901979
Pennington119881975
Arvin120121973
Collegeville119691969
Brawley119991990
Cordova119801980
Gold Hill119991999
Westley120151979
Dorris120171998
Tranquillity120031973
Lockwood119831983
Palo Verde120242003
Hollister120072003
Zamora120211981
Bodega Bay120162002
Ora Loma119731973
Point Reyes120092006
Orland120031983

Common Gallinule Population Trend in Other States

alabamaarizonaarkansasconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippinevadanew-jerseynew-yorknorth-carolinaohiopennsylvaniasouth-carolinatennesseetexasutahvermontwisconsin

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