BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Common Gallinule In Coastal California

All regionsCoastal CaliforniaWetland birds

Common Gallinule in Coastal California has collapsed: down 86% on the route-weighted index since 1971.

-86%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 →
22Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
46YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Coastal California: down 86% on the route-weighted index since 1971.

Common Gallinule In Coastal California Population Forecast

If the recent trend holds, Common Gallinule in Coastal California is projected to stay roughly flat through 2026, near 0.36 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±2478.6%, with 0% of held-out values landing inside the 95% band.

n/aChange by 2026TrendPercent 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 →
0.36Projected 2026 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.7195% 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 →
±2478.6%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, Common Gallinule in Coastal California is projected to stay roughly flat through 2026, near 0.36 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±2478.6%, with 0% of held-out values landing inside the 95% band.19692026
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 →
20220.340.000.69
20230.340.000.70
20240.350.000.70
20250.350.000.70
20260.360.000.71

Routes In Coastal California

Routes recording Common Gallinule in Coastal 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 →
GlennCALIFORNIA122009
GravesboroCALIFORNIA41971
AuburnCALIFORNIA31975
BakersfieldCALIFORNIA21970
CoyoteCALIFORNIA21983
OnealsCALIFORNIA21979
PenningtonCALIFORNIA11988
CollegevilleCALIFORNIA11969
HollisterCALIFORNIA12007
Point ReyesCALIFORNIA12009
OrlandCALIFORNIA12003
OnoCALIFORNIA12011
FolsomCALIFORNIA12003
ArvinCALIFORNIA12012
CordovaCALIFORNIA11980
Gold HillCALIFORNIA11999
WestleyCALIFORNIA12015
TranquillityCALIFORNIA12003
LockwoodCALIFORNIA11983
ZamoraCALIFORNIA12021
Ora LomaCALIFORNIA11973
Buena VistaCALIFORNIA11993

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