BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

California Gull In Sierra Nevada

All regionsSierra NevadaWetland birds

California Gull in Sierra Nevada has collapsed: down 98% on the route-weighted index since 1974.

-98%Since 1974
10Routes In Region
39Years

Notable Signals

long arc declinecomputed index

California Gull has collapsed in Sierra Nevada: down 98% on the route-weighted index since 1974.

Forecast

If the recent trend holds, California Gull in Sierra Nevada is projected to stay roughly flat through 2022, near 1.1 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±3795.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2022
1.1Projected 2022 index
0.00–3.895% range
±3795.9%Backtest error
19722022
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
20181.10.003.8
20191.10.003.8
20201.10.003.8
20211.10.003.8
20221.10.003.8

Routes In Sierra Nevada

Routes recording California Gull in Sierra Nevada.
GoumazCALIFORNIA802004
Tuolumne GroveCALIFORNIA151979
WoodfordsCALIFORNIA31983
LakeshoreCALIFORNIA31992
Eagle LakeCALIFORNIA12014
DardanelleCALIFORNIA12015
Bass LakeCALIFORNIA11976
SattleyCALIFORNIA12017
GeneseeCALIFORNIA12013
CrestviewCALIFORNIA12004

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