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

Black Swift In Sierra Nevada

All regionsSierra NevadaAerial insectivores

Black Swift in Sierra Nevada has collapsed: down 86% on the route-weighted index since 1977.

-86%Since 1977TrendPercent 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 →
7Routes 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 →
14YearsYears 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 →

Black Swift has collapsed in Sierra Nevada: down 86% on the route-weighted index since 1977.

Routes In Sierra Nevada

Routes recording Black Swift in Sierra Nevada.
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 →
Bass LakeCALIFORNIA12008
Silver CityCALIFORNIA11980
Kings CanyonCALIFORNIA12004
Hat CreekCALIFORNIA12004
LakeshoreCALIFORNIA11987
CoultervilleCALIFORNIA11998
KernvilleCALIFORNIA12008

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