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

Lazuli Bunting In Coastal California

All regionsCoastal CaliforniaGeneralists

Lazuli Bunting in Coastal California has risen sharply: up 52% on the route-weighted index since 1970.

+52%Since 1970TrendPercent 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 →
98Routes 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 →
56YearsYears 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 increasecomputed 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 →

Lazuli Bunting has risen sharply in Coastal California: up 52% on the route-weighted index since 1970.

Lazuli Bunting In Coastal California Population Forecast

If the recent trend holds, Lazuli Bunting in Coastal California is projected to stay roughly flat through 2029, near 1.9 (95% range 0.63–3.1). A 5-year backtest shows a typical error of ±110%, with 80% of held-out values landing inside the 95% band.

+7%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 →
1.9Projected 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 →
0.63–3.195% 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 →
±110%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, Lazuli Bunting in Coastal California is projected to stay roughly flat through 2029, near 1.9 (95% range 0.63–3.1). A 5-year backtest shows a typical error of ±110%, with 80% of held-out values landing inside the 95% band.19682029
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 →
20251.80.613.1
20261.80.623.1
20271.90.623.1
20281.90.633.1
20291.90.633.1

Routes In Coastal California

Routes recording Lazuli Bunting 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 →
Elsinore MtnCALIFORNIA302024
AnzaCALIFORNIA161995
PowayCALIFORNIA101980
OnoCALIFORNIA102011
Oak GroveCALIFORNIA92023
Lake SuccessCALIFORNIA81996
JacksonCALIFORNIA81986
Mt BaldyCALIFORNIA72024
ReddingCALIFORNIA71983
CohassetCALIFORNIA62023
Green ValleyCALIFORNIA62023
Anza 2CALIFORNIA62024
Red BluffCALIFORNIA52024
Yokohl ValCALIFORNIA51997
Foster ParkCALIFORNIA51994
Harbor LakeCALIFORNIA51975
S CatalinaCALIFORNIA52019
El ToroCALIFORNIA51986
FallsvaleCALIFORNIA51981
SangerCALIFORNIA52024
PescaderoCALIFORNIA52024
Lockwood ValCALIFORNIA42019
Mt LagunaCALIFORNIA41987
Lake CachumaCALIFORNIA42016
Waterman GapCALIFORNIA42024

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