BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Rufous-crowned Sparrow In Sierra Nevada

All regionsSierra NevadaGeneralists

Rufous-crowned Sparrow in Sierra Nevada has increased: up 32% on the route-weighted index since 1997.

+32%Since 1997TrendPercent 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 →
6Routes 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 →
25YearsYears 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 Rufous-crowned Sparrow in Sierra Nevada. See the full index history below.

Rufous-crowned Sparrow In Sierra Nevada Population Forecast

If the recent trend holds, Rufous-crowned Sparrow in Sierra Nevada is projected to rise about 313% by 2029 — from 0.05 in 2024 to a central estimate of 0.22 (95% range 0.01–0.43). A 5-year backtest shows a typical error of ±103.4%, with 100% of held-out values landing inside the 95% band.

+313%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 →
0.22Projected 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 →
0.01–0.4395% 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 →
±103.4%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 Nevada is projected to rise about 313% by 2029 — from 0.05 in 2024 to a central estimate of 0.22 (95% range 0.01–0.43). A 5-year backtest shows a typical error of ±103.4%, with 100% of held-out values landing inside the 95% band.19722029
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 →
20250.210.000.42
20260.210.000.43
20270.210.000.43
20280.220.000.43
20290.220.010.43

Routes In Sierra Nevada

Routes recording Rufous-crowned Sparrow in Sierra Nevada.
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 →
Silver CityCALIFORNIA62013
Forest HillCALIFORNIA42022
KernvilleCALIFORNIA22008
Bass LakeCALIFORNIA12019
Kings CanyonCALIFORNIA12024
CoultervilleCALIFORNIA12007

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