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

Song Sparrow In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Song Sparrow in Sierra Madre Occidental has increased: up 38% on the route-weighted index since 1984.

+38%Since 1984TrendPercent 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 →
10Routes 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 →
40YearsYears 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 Song Sparrow in Sierra Madre Occidental. See the full index history below.

Song Sparrow In Sierra Madre Occidental Population Forecast

If the recent trend holds, Song Sparrow in Sierra Madre Occidental is projected to fall about 42% by 2029 — from 0.28 in 2024 to a central estimate of 0.16 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±69%, with 100% of held-out values landing inside the 95% band.

-42%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 →
0.16Projected 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 →
±69%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, Song Sparrow in Sierra Madre Occidental is projected to fall about 42% by 2029 — from 0.28 in 2024 to a central estimate of 0.16 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±69%, with 100% of held-out values landing inside the 95% band.19792029
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 →
20250.170.000.41
20260.170.000.41
20270.170.000.41
20280.160.000.41
20290.160.000.41

Routes In Sierra Madre Occidental

Routes recording Song Sparrow 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 →
CutterARIZONA32014
Carr MtnARIZONA32024
BlueARIZONA11987
PomereneARIZONA12024
PatagoniaARIZONA12024
MaineARIZONA12003
Skull ValleyARIZONA12015
Tonto Vill.ARIZONA12019
RedingtonARIZONA12017
SprucedaleARIZONA12007

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