BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Black Swift In Coastal California

All regionsCoastal CaliforniaAerial insectivores

Black Swift in Coastal California has held roughly steady: down 4% on the route-weighted index since 1973.

-4%Since 1973TrendPercent 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 →
19Routes 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 →
31YearsYears 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 →

No notable trend signals for Black Swift in Coastal California. See the full index history below.

Black Swift In Coastal California Population Forecast

If the recent trend holds, Black Swift in Coastal California is projected to rise about 28% by 2029 — from 0.06 in 2024 to a central estimate of 0.08 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±37.3%, with 100% of held-out values landing inside the 95% band.

+28%Change by 2029TrendPercent 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 →
0.08Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4195% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±37.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Black Swift in Coastal California is projected to rise about 28% by 2029 — from 0.06 in 2024 to a central estimate of 0.08 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±37.3%, with 100% of held-out values landing inside the 95% band.19712029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.090.000.41
20260.090.000.41
20270.090.000.41
20280.080.000.41
20290.080.000.41

Routes In Coastal California

Routes recording Black Swift in Coastal 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 →
Yolla BollyCALIFORNIA481980
SangerCALIFORNIA102018
Lake HemetCALIFORNIA81986
White RiverCALIFORNIA71992
Cal Hot SpgsCALIFORNIA72016
Angelus OaksCALIFORNIA52017
FallsvaleCALIFORNIA41975
RumseyCALIFORNIA31994
Orange CoveCALIFORNIA32004
CohassetCALIFORNIA31980
Carmel ValCALIFORNIA31983
JacksonCALIFORNIA31992
Waterman GapCALIFORNIA32024
Lake SuccessCALIFORNIA21996
LockwoodCALIFORNIA21986
CoyoteCALIFORNIA21984
Foster ParkCALIFORNIA11971
Morro BayCALIFORNIA12004
Mt BaldyCALIFORNIA12015

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