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

Gray Vireo Population Trend in California

All statesForest birds

Gray Vireo in California has collapsed: down 83% on the route-weighted index since 1979.

-83%Since 1979TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
16YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

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

No notable trend signals for Gray Vireo in California. See the full index history below.

Gray Vireo Survey Routes in California

Routes recording Gray Vireo in California.
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 →
Big Bear119831970
Cleveland Nf120152005
Ivanpah119951995

Gray Vireo Population Trend in Other States

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