BirdAnalyst
Species · California · BBS 2025 Release · 1966–2024

Great Blue Heron Population Trend in California

All statesWetland birds

Great Blue Heron in California has edged up: up 19% on the route-weighted index since 1970.

+19%Since 1970
156Routes In State
56Years

Notable Great Blue Heron Trends in California

No notable trend signals for Great Blue Heron in California. See the full index history below.

Great Blue Heron Population Forecast in California

If the recent trend holds, Great Blue Heron in California is projected to rise about 22% by 2029 — from 0.67 in 2024 to a central estimate of 0.81 (95% range 0.21–1.4). A 5-year backtest shows a typical error of ±84%, with 80% of held-out values landing inside the 95% band.

+22%Change by 2029
0.81Projected 2029 index
0.21–1.495% range
±84%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
20250.830.231.4
20260.830.221.4
20270.820.221.4
20280.820.211.4
20290.810.211.4

Great Blue Heron Survey Routes in California

Routes recording Great Blue Heron in California.
Iron Gate2420191988
Hollister1020071975
Staten Is.820241994
Hughson720241969
Shafter719881987
Glenn720231971
Ora Loma720241972
Yreka720191973
Lake Success619811972
Collegeville 2620232007
Horse Creek520191970
Auburn519791970
Crescent Cty420221972
Bass Lake420091978
Fairfax420241972
Niland420241974
Dorris420191972
Clear Lk Res420181972
Redwood N.P.420101995
Ivanpah320072007
Lake Berryessa320242023
Arvin320211988
Atwater320121972
Jackson319861973
Coyote320241972

Great Blue Heron Population Trend in Other States

alabamaalaskaarizonaarkansascoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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