BirdAnalyst
Species · BCR 34 · BBS 2026 Release · 1966–2025

Rufous-crowned Sparrow In Sierra Madre Occidental

All regionsSierra Madre OccidentalArid-land birds

Rufous-crowned Sparrow in Sierra Madre Occidental has surged: up 118% on the route-weighted index since 1970.

+118%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 →
28Routes 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 →
57YearsYears 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 increasecomputed 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 →

Rufous-crowned Sparrow has surged in Sierra Madre Occidental: up 118% on the route-weighted index since 1970.

Rufous-crowned Sparrow In Sierra Madre Occidental Population Forecast

If the recent trend holds, Rufous-crowned Sparrow in Sierra Madre Occidental is projected to rise about 38% by 2030 — from 1.7 in 2025 to a central estimate of 2.3 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±28.4%, with 100% of held-out values landing inside the 95% band.

+38%Change by 2030TrendPercent 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 →
2.3Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–7.195% 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 →
±28.4%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, Rufous-crowned Sparrow in Sierra Madre Occidental is projected to rise about 38% by 2030 — from 1.7 in 2025 to a central estimate of 2.3 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±28.4%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20262.50.007.3
20272.50.007.2
20282.40.007.2
20292.40.007.1
20302.30.007.1

Routes In Sierra Madre Occidental

Routes recording Rufous-crowned 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 →
CutterARIZONA162014
Emory PassNEW-MEXICO112025
SprucedaleARIZONA102025
Peña BlancaARIZONA82025
PortalARIZONA52025
DragoonARIZONA52009
Forest LakesARIZONA32024
RedingtonARIZONA32025
Carr MtnARIZONA32025
Aztec PeakARIZONA21978
PomereneARIZONA22006
SunizonaARIZONA21997
Bartlett ResARIZONA22025
MagdalenaNEW-MEXICO22024
PrescottARIZONA12017
San SimonARIZONA12016
PatagoniaARIZONA12025
Skull ValleyARIZONA12019
PinetopARIZONA12018
AlpineARIZONA12015
AmadoARIZONA12019
SahuaritaARIZONA12019
McnealARIZONA12023
Skull Valley 2ARIZONA12025
Sunizona 2ARIZONA12025

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.