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

Varied Bunting In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Varied Bunting in Sierra Madre Occidental has declined: down 33% on the route-weighted index since 1971.

-33%Since 1971TrendPercent 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 →
8Routes 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 →
51YearsYears 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 Varied Bunting in Sierra Madre Occidental. See the full index history below.

Varied Bunting In Sierra Madre Occidental Population Forecast

If the recent trend holds, Varied Bunting in Sierra Madre Occidental is projected to fall about 52% by 2029 — from 0.61 in 2024 to a central estimate of 0.29 (95% range 0.00–0.78). A 5-year backtest shows a typical error of ±63.4%, with 80% of held-out values landing inside the 95% band.

-52%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 →
0.29Projected 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 →
0.00–0.7895% 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 →
±63.4%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, Varied Bunting in Sierra Madre Occidental is projected to fall about 52% by 2029 — from 0.61 in 2024 to a central estimate of 0.29 (95% range 0.00–0.78). A 5-year backtest shows a typical error of ±63.4%, 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 →
20250.300.000.79
20260.300.000.79
20270.300.000.79
20280.290.000.79
20290.290.000.78

Routes In Sierra Madre Occidental

Routes recording Varied 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 →
PomereneARIZONA72024
PatagoniaARIZONA42024
AmadoARIZONA42023
Peña BlancaARIZONA32023
RedingtonARIZONA12021
SahuaritaARIZONA12019
McnealARIZONA12021
PortalARIZONA12005

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