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

Western Grebe Population Trend in California

All statesWetland birds

Western Grebe in California has collapsed: down 80% on the route-weighted index since 1988.

-80%Since 1988
38Routes In State
38Years

Notable Western Grebe Trends in California

long arc declinecomputed index

Western Grebe has collapsed in California: down 80% on the route-weighted index since 1988.

Western Grebe Population Forecast in California

If the recent trend holds, Western Grebe in California is projected to rise about 206% by 2029 — from 0.66 in 2024 to a central estimate of 2.0 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±3863.2%, with 100% of held-out values landing inside the 95% band.

+206%Change by 2029
2.0Projected 2029 index
0.00–7.295% range
±3863.2%Backtest error
19862029
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
20252.10.007.3
20262.10.007.3
20272.10.007.2
20282.00.007.2
20292.00.007.2

Western Grebe Survey Routes in California

Routes recording Western Grebe in California.
Iron Gate12420191988
Dorris5620191986
Bartlett Sps2920181986
Coyote2020242000
San Ysidro1619901990
Eagle Lake1320241986
Hughson1320241987
Navarro1019901990
Coalinga820011998
South Lake520062006
Harbor Lake 2520242018
Glen Ellen 3520242024
Fish Rock320101988
Madeline320171999
Oroville320241993
Chilcoot319981998
Elizabeth Lk220162016
Sattley220191989
Macdoel219981989
Clear Lk Res220181986
Laytonville219891988
Morro Bay219921992
Folsom220091992
Adelaida219931993
Nubieber120171986

Western Grebe Population Trend in Other States

arizonacoloradoidahokansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoregonsouth-dakotautahwashingtonwyoming

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