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

Great Blue Heron In Coastal California

All regionsCoastal CaliforniaWetland birds

Great Blue Heron in Coastal California has risen sharply: up 70% on the route-weighted index since 1970.

+70%Since 1970
83Routes In Region
56Years

Notable Signals

long arc increasecomputed index

Great Blue Heron has risen sharply in Coastal California: up 70% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Great Blue Heron in Coastal California is projected to fall about 13% by 2029 — from 1.1 in 2024 to a central estimate of 1.00 (95% range 0.13–1.9). A 5-year backtest shows a typical error of ±56.6%, with 100% of held-out values landing inside the 95% band.

-13%Change by 2029
1.00Projected 2029 index
0.13–1.995% range
±56.6%Backtest error
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 index95% low95% high
20251.00.151.9
20261.00.141.9
20271.00.141.9
20281.00.131.9
20291.000.131.9

Routes In Coastal California

Routes recording Great Blue Heron in Coastal California.
HollisterCALIFORNIA102007
Staten Is.CALIFORNIA82024
HughsonCALIFORNIA72024
ShafterCALIFORNIA71988
GlennCALIFORNIA72023
Ora LomaCALIFORNIA72024
Lake SuccessCALIFORNIA61981
Collegeville 2CALIFORNIA62023
AuburnCALIFORNIA51979
FairfaxCALIFORNIA42024
Lake BerryessaCALIFORNIA32024
ArvinCALIFORNIA32021
AtwaterCALIFORNIA32012
JacksonCALIFORNIA31986
CoyoteCALIFORNIA32024
PolomaCALIFORNIA32021
CalpellaCALIFORNIA21986
RumseyCALIFORNIA22007
BakersfieldCALIFORNIA22015
AdelaidaCALIFORNIA22024
SangerCALIFORNIA22024
CrestonCALIFORNIA22024
White RiverCALIFORNIA21992
CordovaCALIFORNIA21981
Gold HillCALIFORNIA22024

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