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

Double-crested Cormorant Population Trend in California

All statesWetland birds

Double-crested Cormorant in California has risen sharply: up 69% on the route-weighted index since 1974.

+69%Since 1974
73Routes In State
52Years

Notable Double-crested Cormorant Trends in California

long arc increasecomputed index

Double-crested Cormorant has risen sharply in California: up 69% on the route-weighted index since 1974.

Double-crested Cormorant Population Forecast in California

If the recent trend holds, Double-crested Cormorant in California is projected to rise about 113% by 2029 — from 1.5 in 2024 to a central estimate of 3.2 (95% range 0.26–6.2). A 5-year backtest shows a typical error of ±3169.6%, with 20% of held-out values landing inside the 95% band.

+113%Change by 2029
3.2Projected 2029 index
0.26–6.295% range
±3169.6%Backtest error
19722029
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
20253.10.146.0
20263.10.176.1
20273.10.206.1
20283.20.236.1
20293.20.266.2

Double-crested Cormorant Survey Routes in California

Routes recording Double-crested Cormorant in California.
Dorris7220191972
Cedarville6020242024
Fairfax3220241972
Iron Gate2720191988
Arvin2720212013
Hughson1820242000
Hat Creek1219871987
Westley1020241996
Eagle Lake820072002
Honeydew720161977
Hollister720071995
Staten Is.720241998
Creston620142014
Moraga520241998
Ingalls519981974
Likely420151978
Genesee420152008
Downieville420072007
Oneals420002000
Point Reyes420082007
Niland420241979
Mesa Grande420102010
Buena Vista420192019
Nubieber319931977
Red Bluff320031987

Double-crested Cormorant 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.