BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Lazuli Bunting In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Lazuli Bunting in Sierra Madre Occidental has collapsed: down 89% on the route-weighted index since 1981.

-89%Since 1981TrendPercent 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 →
9Routes 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 →
19YearsYears 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 →

Lazuli Bunting has collapsed in Sierra Madre Occidental: down 89% on the route-weighted index since 1981.

Forecast

If the recent trend holds, Lazuli Bunting in Sierra Madre Occidental is projected to stay roughly flat through 2027, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±288.6%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.00Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.3495% 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 →
±288.6%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 Sierra Madre Occidental is projected to stay roughly flat through 2027, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±288.6%, with 100% of held-out values landing inside the 95% band.19742027
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 →
20230.000.000.34
20240.000.000.34
20250.000.000.34
20260.000.000.34
20270.000.000.34

Routes In Sierra Madre Occidental

Routes recording Lazuli Bunting in Sierra Madre Occidental.
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 →
MaineARIZONA121997
Aztec PeakARIZONA71974
FlagstaffARIZONA22000
BlueARIZONA21988
ReserveNEW-MEXICO21996
PrescottARIZONA12013
PomereneARIZONA12022
PatagoniaARIZONA12015
Carr MtnARIZONA11988

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