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

Great Egret In Coastal California

All regionsCoastal CaliforniaWetland birds

Great Egret in Coastal California has surged: up 40× on the route-weighted index since 1971.

40×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 →
56Routes 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 →
55YearsYears 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 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 →

Great Egret has surged in Coastal California: up 40× on the route-weighted index since 1971.

Great Egret In Coastal California Population Forecast

If the recent trend holds, Great Egret in Coastal California is projected to rise about 90% by 2029 — from 1.8 in 2024 to a central estimate of 3.5 (95% range 1.3–5.6). A 5-year backtest shows a typical error of ±82.9%, with 80% of held-out values landing inside the 95% band.

+90%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 →
3.5Projected 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 →
1.3–5.695% 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 →
±82.9%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, Great Egret in Coastal California is projected to rise about 90% by 2029 — from 1.8 in 2024 to a central estimate of 3.5 (95% range 1.3–5.6). A 5-year backtest shows a typical error of ±82.9%, with 80% 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 →
20253.31.25.5
20263.41.25.5
20273.41.25.6
20283.41.35.6
20293.51.35.6

Routes In Coastal California

Routes recording Great Egret 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 →
GlennCALIFORNIA282023
HughsonCALIFORNIA172024
Staten Is.CALIFORNIA142024
AtwaterCALIFORNIA112012
Collegeville 2CALIFORNIA112023
Ora LomaCALIFORNIA102024
FairfaxCALIFORNIA82024
WestleyCALIFORNIA82024
Buena VistaCALIFORNIA82019
ZamoraCALIFORNIA72024
AthloneCALIFORNIA72007
SisquocCALIFORNIA62000
TranquillityCALIFORNIA62023
PenningtonCALIFORNIA52024
OrlandCALIFORNIA42019
Tracy 2CALIFORNIA42015
Jofegan 2CALIFORNIA42024
PowayCALIFORNIA31977
MoragaCALIFORNIA32024
Bartlett SpsCALIFORNIA32017
Mark WestCALIFORNIA32024
CoyoteCALIFORNIA32023
CopperopolisCALIFORNIA32019
OnealsCALIFORNIA32024
Red BluffCALIFORNIA22019

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