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

Green Heron In Coastal California

All regionsCoastal CaliforniaWetland birds

Green Heron in Coastal California has increased: up 38% on the route-weighted index since 1972.

+38%Since 1972TrendPercent 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 →
63Routes 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 →
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 SignalsNotable 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 Green Heron in Coastal California. See the full index history below.

Green Heron In Coastal California Population Forecast

If the recent trend holds, Green Heron in Coastal California is projected to rise about 197% by 2029 — from 0.06 in 2024 to a central estimate of 0.19 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±302.4%, with 100% of held-out values landing inside the 95% band.

+197%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 →
0.19Projected 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 →
0.00–0.4395% 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 →
±302.4%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, Green Heron in Coastal California is projected to rise about 197% by 2029 — from 0.06 in 2024 to a central estimate of 0.19 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±302.4%, 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 →
20250.190.000.43
20260.190.000.43
20270.190.000.43
20280.190.000.43
20290.190.000.43

Routes In Coastal California

Routes recording Green Heron 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 →
CohassetCALIFORNIA42018
PowayCALIFORNIA41980
GlennCALIFORNIA42009
Ora LomaCALIFORNIA31974
CalpellaCALIFORNIA21981
Foster ParkCALIFORNIA21981
San YsidroCALIFORNIA21992
HollisterCALIFORNIA21998
Orange CoveCALIFORNIA22011
OnoCALIFORNIA22010
SisquocCALIFORNIA21995
ShafterCALIFORNIA21988
Glen EllenCALIFORNIA22002
Collegeville 2CALIFORNIA22009
Red BluffCALIFORNIA12015
PenningtonCALIFORNIA12004
RumseyCALIFORNIA12007
RiovistaCALIFORNIA11971
CollegevilleCALIFORNIA12002
HughsonCALIFORNIA12005
GravesboroCALIFORNIA11990
Yokohl ValCALIFORNIA11996
Santa YnezCALIFORNIA11977
Harbor LakeCALIFORNIA11981
CoalingaCALIFORNIA12009

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