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

Rufous-crowned Sparrow In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Rufous-crowned Sparrow in Sierra Madre Occidental has surged: up 130% on the route-weighted index since 1970.

+130%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 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 130% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Rufous-crowned Sparrow in Sierra Madre Occidental is projected to fall about 29% by 2029 — from 3.5 in 2024 to a central estimate of 2.5 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±20.7%, with 100% of held-out values landing inside the 95% band.

-29%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 →
2.5Projected 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 →
0.00–7.295% 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 →
±20.7%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 fall about 29% by 2029 — from 3.5 in 2024 to a central estimate of 2.5 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±20.7%, 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 →
20252.70.007.4
20262.60.007.4
20272.60.007.3
20282.50.007.3
20292.50.007.2

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 →
Peña BlancaARIZONA212024
CutterARIZONA162014
Emory PassNEW-MEXICO102024
PatagoniaARIZONA82024
RedingtonARIZONA82023
PortalARIZONA82024
Bartlett ResARIZONA52024
Carr MtnARIZONA52024
DragoonARIZONA52009
ReserveNEW-MEXICO42022
Forest LakesARIZONA32024
Aztec PeakARIZONA21978
PomereneARIZONA22006
SunizonaARIZONA21997
SprucedaleARIZONA22023
Sunizona 2ARIZONA22015
MagdalenaNEW-MEXICO22024
PrescottARIZONA12017
San SimonARIZONA12016
Skull ValleyARIZONA12019
PinetopARIZONA12018
AlpineARIZONA12015
AmadoARIZONA12019
SahuaritaARIZONA12019
McnealARIZONA12023

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