BirdAnalyst
Species · BCR 33 · BBS 2025 Release · 1966–2024

California Gull In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsWetland birds

California Gull in Sonoran and Mojave Deserts has collapsed: down 96% on the route-weighted index since 1993.

-96%Since 1993TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
3Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
17YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

California Gull has collapsed in Sonoran and Mojave Deserts: down 96% on the route-weighted index since 1993.

Routes In Sonoran and Mojave Deserts

Routes recording California Gull in Sonoran and Mojave Deserts.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Haiwee ResCALIFORNIA502004
NilandCALIFORNIA32024
Eureka ValCALIFORNIA12014

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