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

Black-throated Sparrow In Sierra Madre Occidental

All regionsSierra Madre OccidentalArid-land birds

Black-throated Sparrow in Sierra Madre Occidental has fallen sharply: down 57% on the route-weighted index since 1970.

-57%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 →
27Routes 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 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 →

Black-throated Sparrow has fallen sharply in Sierra Madre Occidental: down 57% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Black-throated Sparrow in Sierra Madre Occidental is projected to fall about 70% by 2029 — from 24 in 2024 to a central estimate of 7.2 (95% range 0.00–29). A 5-year backtest shows a typical error of ±64.2%, with 100% of held-out values landing inside the 95% band.

-70%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 →
7.2Projected 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 →
0.00–2995% 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 →
±64.2%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, Black-throated Sparrow in Sierra Madre Occidental is projected to fall about 70% by 2029 — from 24 in 2024 to a central estimate of 7.2 (95% range 0.00–29). A 5-year backtest shows a typical error of ±64.2%, with 100% 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 →
20259.20.0031
20268.70.0031
20278.20.0030
20287.70.0030
20297.20.0029

Routes In Sierra Madre Occidental

Routes recording Black-throated 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 →
San SimonARIZONA1362024
PomereneARIZONA822024
RedingtonARIZONA802023
Carr MtnARIZONA792024
CutterARIZONA562014
McnealARIZONA292024
DragoonARIZONA272009
Bartlett ResARIZONA222024
Sunizona 2ARIZONA192024
PortalARIZONA182024
Aztec PeakARIZONA171978
MagdalenaNEW-MEXICO162024
SunizonaARIZONA121997
RuckerARIZONA112009
AmadoARIZONA102023
SahuaritaARIZONA102024
Vicks PeakNEW-MEXICO82024
Forest LakesARIZONA72024
Mormon LakeARIZONA41974
Clay SpringARIZONA42024
PatagoniaARIZONA32023
PrescottARIZONA21984
Skull ValleyARIZONA22024
Peña BlancaARIZONA12024
MaineARIZONA12006

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