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

Lazuli Bunting Population Trend in California

All statesGeneralists

Lazuli Bunting in California has held roughly steady: up 7% on the route-weighted index since 1970.

+7%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 →
202Routes 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 →
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 Lazuli Bunting 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 Lazuli Bunting in California. See the full index history below.

Lazuli Bunting Population Forecast in California

If the recent trend holds, Lazuli Bunting in California is projected to stay roughly flat through 2029, near 3.5 (95% range 2.3–4.7). A 5-year backtest shows a typical error of ±64.1%, with 40% of held-out values landing inside the 95% band.

-1%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 →
3.5Projected 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 →
2.3–4.795% 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 →
±64.1%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 California is projected to stay roughly flat through 2029, near 3.5 (95% range 2.3–4.7). A 5-year backtest shows a typical error of ±64.1%, with 40% 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 →
20253.42.24.6
20263.42.24.7
20273.52.24.7
20283.52.34.7
20293.52.34.7

Lazuli Bunting Survey Routes in California

Routes recording Lazuli Bunting 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 →
Pollock Pines5220241997
Alderpoint4320121974
Martins Fy3720091976
Lakeshore3220241973
Elsinore Mtn3020241970
Paxton3020241998
Lumberyard1620241996
Anza1619951976
Honeydew1520171968
Tuolumne Grove1520241974
Friday Ridge1520241994
Rio Dell1420121972
Genesee1420241972
Kings Canyon1320241972
Kernville1320082008
South Fork Mtn1320222000
Horse Creek1220191970
Iron Gate1220191988
Offield Mtn1120131973
Pilot Creek1119961994
Poway1019801973
Ono1020111984
Longvale1020231972
Holmes920241968
Oak Grove920231971

Lazuli Bunting Population Trend in Other States

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