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

Snowy Egret In Coastal California

All regionsCoastal CaliforniaWetland birds

Snowy Egret in Coastal California has surged: up 138% on the route-weighted index since 1973.

+138%Since 1973TrendPercent 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 →
32Routes 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 →
53YearsYears 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 →

Snowy Egret has surged in Coastal California: up 138% on the route-weighted index since 1973.

Snowy Egret In Coastal California Population Forecast

If the recent trend holds, Snowy Egret in Coastal California is projected to rise about 261% by 2029 — from 0.34 in 2024 to a central estimate of 1.2 (95% range 0.24–2.2). A 5-year backtest shows a typical error of ±194.4%, with 60% of held-out values landing inside the 95% band.

+261%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 →
1.2Projected 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 →
0.24–2.295% 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 →
±194.4%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, Snowy Egret in Coastal California is projected to rise about 261% by 2029 — from 0.34 in 2024 to a central estimate of 1.2 (95% range 0.24–2.2). A 5-year backtest shows a typical error of ±194.4%, with 60% of held-out values landing inside the 95% band.19712029
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 →
20251.20.172.2
20261.20.192.2
20271.20.212.2
20281.20.222.2
20291.20.242.2

Routes In Coastal California

Routes recording Snowy 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 →
RiovistaCALIFORNIA192007
GlennCALIFORNIA172022
FairfaxCALIFORNIA102024
WestleyCALIFORNIA92021
HughsonCALIFORNIA52018
Cp. PendletonCALIFORNIA42004
Harbor Lake 2CALIFORNIA32022
Staten Is.CALIFORNIA32024
El ToroCALIFORNIA21996
ZamoraCALIFORNIA22023
CoyoteCALIFORNIA22024
PenningtonCALIFORNIA12022
Harbor LakeCALIFORNIA11991
MorenoCALIFORNIA12022
San YsidroCALIFORNIA11989
HollisterCALIFORNIA12001
CoalingaCALIFORNIA12005
Morro BayCALIFORNIA11992
OrlandCALIFORNIA12013
PowayCALIFORNIA11977
VentucopaCALIFORNIA11980
ArvinCALIFORNIA12022
AtwaterCALIFORNIA12012
OrovilleCALIFORNIA12006
TranquillityCALIFORNIA12003

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